Welcome to kwargs’s docs!
kwargshelper
A python package for working with kwargs.
Allows for validation of args passed in via **kwargs in various ways.
Such as type checking, rules checking, error handeling.
Many built in rules that make validation of input simple and effective. Easily create and add new rules.
Various callbacks to hook each kwarg with rich set of options for fine control.
Docs
Read the docs here
Installation
You can install the Version Class from PyPI
pip install kwargshelper
KwargsHelper Class
Helper class for working with python **kwargs in a class constructor
Assigns values of **kwargs to an exising class with type checking and rules
Parse kwargs with suport for rules that can be extended that validate any arg of kwargs. Type checking of any type.
Callback function for before update that includes a Cancel Option.
Many other options avaliable for more complex usage.
KwArg Class
Helper class for working with python **kwargs in a method/function
Wrapper for KwargsHelper Class.
Assigns values of **kwargs to itself with validation
Parse kwargs with suport for rules that can be extended that validate any arg of kwargs. Type checking of any type.
Callback function for before update that includes a Cancel Option.
Many other options avaliable for more complex usage.
Decorator Classes
Decorators that can applied to function that validate arguments.
Decorators for Type checking and Rule testing is built in.
The following example ensures all function args are a positive int or a positive float.
from kwhelp.decorator import RuleCheckAny
import kwhelp.rules as rules
@RuleCheckAny(rules.RuleIntPositive, rules.RuleFloatPositive)
def speed_msg(speed, limit, **kwargs) -> str:
if limit > speed:
msg = f"Current speed is '{speed}'. You may go faster as the limit is '{limit}'."
elif speed == limit:
msg = f"Current speed is '{speed}'. You are at the limit."
else:
msg = f"Please slow down limit is '{limit}' and you are currenlty going '{speed}'."
if 'hours' in kwargs:
msg = msg + f" Current driving hours is '{kwargs['hours']}'"
return msg
TOC
Usage
KwargsHelper
Assign Default Value
Default value can be assigned by adding default args to assign() method.
from kwhelp import KwargsHelper
import kwhelp.rules as rules
class MyClass:
def __init__(self, **kwargs):
self._duration = "Long"
kw = KwargsHelper(self, {**kwargs})
kw.assign(key="speed", require=True, rules_all=[rules.RuleIntPositive])
kw.assign(key="unit", default="MPH", rules_all=[rules.RuleStrNotNullOrEmpty])
kw.assign(key="duration", default=self._duration,
rules=[rules.RuleStrNotNullOrEmpty])
>>> myclass = MyClass(speed=123, unit="KPH")
>>> print(myclass._speed)
123
>>> print(myclass._unit)
KPH
>>> print(myclass._duration)
Long
>>> myclass = MyClass(speed=123, duration="Short")
>>> print(myclass._speed)
123
>>> print(myclass._unit)
MPH
>>> print(myclass._duration)
Short
Assign Field Value
Field value can be assigned by adding field arg to assign() method.
By default field values are key values with _ prepended. If key="speed" then field
defaults to _speed and thus attribute with the name of _speed is a assigned to class instance.
Setting field arg overrides attribute name that is assigned to current class instance.
from kwhelp import KwargsHelper
import kwhelp.rules as rules
class MyClass:
def __init__(self, **kwargs):
kw = KwargsHelper(self, {**kwargs})
kw.assign(key="speed", field="race_speed", require=True,
rules_all=[rules.RuleIntPositive])
kw.assign(key="unit", field="unit", default="MPH",
rules_all=[rules.RuleStrNotNullOrEmpty])
>>> myclass = MyClass(speed=123)
>>> print(myclass.race_speed)
123
>>> print(myclass.unit)
MPH
>>> myclass = MyClass(speed=123, unit="KPH")
>>> print(myclass._speed)
123
>>> print(myclass._unit)
KPH
Note
Default prefix for all field can be set by setting field_prefix arg of KwargsHelper constructor.
Assign Require Arg
Required args can be done by adding require args to assign() method.
If a required args is missing then a ValueError will be raised.
from kwhelp import KwargsHelper
class MyClass:
def __init__(self, **kwargs):
kw = KwargsHelper(self, {**kwargs})
kw.assign(key="speed", require=True)
kw.assign(key="unit")
>>> myclass = MyClass(speed=123, unit="KPH")
>>> print(myclass._speed)
123
>>> print(myclass._unit)
KPH
>>> myclass = MyClass(unit="KPH")
ValueError: MyClass arg 'speed' is required
Assign Rule Checking
Rule checking can be done by adding rules_all and/or rules_any to assign() method.
Rule checking ensures a value of **kwargs values matches all rules before assign to
current instance of class.
All rules
In the following example attribute speed can be a positive float or int zero.
All other values will result in an error. Arg rules_all of assign()
method validates as True only if all IRule match.
Trying to assign any other type or value results in an error.
Custom Rule for a maximum int value of 100
import kwhelp.rules as rules
class RuleIntMax100(rules.IRule):
def validate(self) -> bool:
if self.field_value > 100:
if self.raise_errors:
raise ValueError(
f"Arg error: '{self.key}' must be equal or less than 100")
return False
return True
from kwhelp import rules, KwargsHelper
class MyClass:
def __init__(self, **kwargs):
kw = KwargsHelper(originator=self, obj_kwargs={**kwargs}, field_prefix="")
kw.assign(key="speed", rules_all=[
rules.RuleIntPositive,
RuleIntMax100
])
Assign int.
>>> myclass = MyClass(speed = 12)
>>> print(myclass.speed)
12
Assign int greater then 100.
>>> myclass = MyClass(speed = 126)
kwhelp.exceptions.RuleError: RuleError: Argument: 'speed' failed validation.
Rule 'RuleIntMax100' Failed validation.
Expected all of the following rules to match: RuleIntPositive, RuleIntMax100.
Inner Error Message: ValueError: Arg error: 'speed' must be equal or less than 100
Assign int negative.
>>> myclass = MyClass(speed = -3)
kwhelp.exceptions.RuleError: RuleError: Argument: 'speed' failed validation.
Rule 'RuleIntPositive' Failed validation.
Expected all of the following rules to match: RuleIntPositive, RuleIntMax100.
Inner Error Message: ValueError: Arg error: 'speed' must be a positive int value
Assign float.
>>> myclass = MyClass(speed = 22.4)
kwhelp.exceptions.RuleError: RuleError: Argument: 'speed' failed validation.
Rule 'RuleIntPositive' Failed validation.
Expected all of the following rules to match: RuleIntPositive, RuleIntMax100.
Inner Error Message: TypeError: Argument Error: 'speed' is expecting type of 'int'. Got type of 'float'
Any rules
In the following example attribute speed can be a positive float or int zero.
All other values will result in an error. Arg rules_all of assign()
method validates as True only if all IRule match.
Trying to assign any other type or value results in an error.
from kwhelp import rules, KwargsHelper
class MyClass:
def __init__(self, **kwargs):
kw = KwargsHelper(originator=self, obj_kwargs={**kwargs}, field_prefix="")
kw.assign(key="speed", rules_any=[
rules.RuleFloatPositive,
rules.RuleIntZero
])
Assign int.
>>> myclass = MyClass(speed = 123.55)
>>> print(myclass.speed)
123.55
Assign int zero.
>>> myclass = MyClass(speed = 0)
>>> print(myclass.speed)
0
Assign float zero.
>>> myclass = MyClass(speed = 0.0)
>>> print(myclass.speed)
0.0
Assign int negative.
>>> myclass = MyClass(speed = -123)
kwhelp.exceptions.RuleError: RuleError: Argument: 'speed' failed validation.
Rule 'RuleFloatPositive' Failed validation.
Expected at least one of the following rules to match: RuleFloatPositive, RuleIntZero.
Inner Error Message: TypeError: Argument Error: 'speed' is expecting type of 'float'. Got type of 'int'
Assign str.
>>> myclass = MyClass(speed="a")
kwhelp.exceptions.RuleError: RuleError: Argument: 'speed' failed validation.
Rule 'RuleFloatPositive' Failed validation.
Expected at least one of the following rules to match: RuleFloatPositive, RuleIntZero.
Inner Error Message: TypeError: Argument Error: 'speed' is expecting type of 'float'. Got type of 'str'
Included Rules
Assign Type Checking
Type checking can be done by adding types to assign() method.
Type checking ensures the type of **kwargs values that are assigned to attributes of current instance of class.
In the following example attribute speed can be of type float or of type int.
All other type will result in an error.
from kwhelp import KwargsHelper
class MyClass:
def __init__(self, **kwargs):
kw = KwargsHelper(self, {**kwargs})
kw.assign(key="speed", types=[int, float])
>>> myclass = MyClass(speed=123)
>>> print(myclass._speed)
123
>>> myclass = MyClass(speed=19.8)
>>> print(myclass._speed)
19.8
>>> myclass = MyClass(speed="a")
TypeError: MyClass arg 'speed' is expected to be of '<class 'float'> | <class 'int'>' but got 'str'
Auto_assign Usage
KwargsHelper.auto_assign() method automatically assigns all key-value pairs to class.
Assign with no args
Assigns all of the key, value pairs passed into constructor to class instance,
unless the event is canceled in BeforeAssignAutoEventArgs via
KwargsHelper.add_handler_before_assign_auto() callback.
from kwhelp import KwargsHelper
class MyClass:
def __init__(self, **kwargs):
kw = KwargsHelper(originator=self, obj_kwargs={**kwargs}, field_prefix='')
kw.auto_assign()
>>> myclass = MyClass(speed=123, msg="Hello World")
>>> print(myclass.speed)
123
>>> print(myclass.msg)
Hello World
Assign with type checking
By setting the optional arg types of KwargsHelper.auto_assign()
it is possible to restrict what types can be assigned.
Assigns all of the key, value pairs passed into constructor to class instance if
the value is of type int or float. Any other type results in an error.
from kwhelp import KwargsHelper
class MyClass:
def __init__(self, **kwargs):
kw = KwargsHelper(originator=self, obj_kwargs={**kwargs}, field_prefix='')
kw.auto_assign(types=[int, float])
Any arg assigned with a value of type int or float is automatically assigned.
>>> myclass = MyClass(speed = 123, distance = 557.46)
>>> print(myclass.speed)
123
>>> print(myclass.distance)
557.46
Assigning an arg with a value that is not of type int or float result is an error.
>>> myclass = MyClass(speed = "Fast", distance = 557.46)
TypeError: MyClass arg 'speed' is expected to be of '<class 'int'> | <class 'float'>' but got 'str'
Assign with Rule checking
By setting the optional arg rules_all of KwargsHelper.auto_assign()
it is possible to set rules that must all be met for key, values to be successfully assigned.
from kwhelp import KwargsHelper
import kwhelp.rules as rules
class MyClass:
def __init__(self, **kwargs):
kw = KwargsHelper(originator=self, obj_kwargs={**kwargs}, field_prefix='')
kw.auto_assign(rules_all=[rules.RuleNotNone, rules.RuleFloatPositive])
Any arg assigned with a value of float is automatically assigned.
>>> myclass = MyClass(speed = 99.999, distance = 557.46)
>>> print(myclass.speed)
99.999
>>> print(myclass.distance)
557.46
Assigning an arg with a value that is not float result is an error.
>>> myclass = MyClass(speed = 99.999, distance = 55)
kwhelp.exceptions.RuleError: RuleError: Argument: 'distance' failed validation.
Rule 'RuleFloatPositive' Failed validation.
Expected all of the following rules to match: RuleNotNone, RuleFloatPositive.
Inner Error Message: TypeError: Argument Error: 'distance' is expecting type of 'float'. Got type of 'int'
Assigning an arg with a value that is a negative float result is an error.
>>> myclass = MyClass(speed = 99.999, distance = -128.09)
kwhelp.exceptions.RuleError: RuleError: Argument: 'distance' failed validation.
Rule 'RuleFloatPositive' Failed validation.
Expected all of the following rules to match: RuleNotNone, RuleFloatPositive.
Inner Error Message: ValueError: Arg error: 'distance' must be a positive float value
By setting the optional arg rules_any of KwargsHelper.auto_assign()
it is possible to set rules that must have at least one match for key, values to be successfully assigned.
from kwhelp import KwargsHelper
import kwhelp.rules as rules
class MyClass:
def __init__(self, **kwargs):
kw = KwargsHelper(originator=self, obj_kwargs={**kwargs}, field_prefix='')
kw.auto_assign(rules_any=[rules.RuleIntPositive, rules.RuleFloatPositive])
Any arg assigned with a value of int or float is automatically assigned.
>>> myclass = MyClass(speed = 99.999, distance = 558)
>>> print(myclass.speed)
99.999
>>> print(myclass.distance)
558
Assigning an arg with a value that is not int or float result is an error.
>>> myclass = MyClass(speed = 'Fast', distance = 55)
kwhelp.exceptions.RuleError: RuleError: Argument: 'speed' failed validation.
Rule 'RuleIntPositive' Failed validation.
Expected at least one of the following rules to match: RuleIntPositive, RuleFloatPositive.
Inner Error Message: TypeError: Argument Error: 'speed' is expecting type of 'int'. Got type of 'str'
Assigning an arg with a value that is a negative int result is an error.
>>> myclass = MyClass(speed = 99.999, distance = -35)
kwhelp.exceptions.RuleError: RuleError: Argument: 'distance' failed validation.
Rule 'RuleIntPositive' Failed validation.
Expected at least one of the following rules to match: RuleIntPositive, RuleFloatPositive.
Inner Error Message: ValueError: Arg error: 'distance' must be a positive int value
Auto_assign Callback
KwargsHelper.auto_assign() method automatically assigns all key-value pairs to class.
Assigns all of the key, value pairs passed into constructor to class instance,
unless the event is canceled in BeforeAssignAutoEventArgs via
KwargsHelper.add_handler_before_assign_auto() callback.
MyClass._arg_before_cb() callback method reads conditions before attribue and value are assigned.
If required conditions are not met then cancel can be set.
from kwhelp import KwargsHelper, AfterAssignAutoEventArgs, BeforeAssignAutoEventArgs
class MyClass:
def __init__(self, **kwargs):
kw = KwargsHelper(originator=self, obj_kwargs={**kwargs}, field_prefix="")
kw.add_handler_before_assign_auto(self._arg_before_cb)
kw.add_handler_after_assign_auto(self._arg_after_cb)
kw.auto_assign()
def _arg_before_cb(self, helper: KwargsHelper,
args: BeforeAssignAutoEventArgs) -> None:
# callback function before value assigned to attribute
if args.key == 'loop_count' and args.field_value < 0:
# cancel will raise CancelEventError unless
# KwargsHelper constructor has cancel_error=False
args.cancel = True
if args.key == 'name' and args.field_value == 'unknown':
args.field_value = 'None'
def _arg_after_cb(self, helper: KwargsHelper,
args: AfterAssignAutoEventArgs) -> None:
# callback function after value assigned to attribute
if args.key == 'name' and args.field_value == 'unknown':
raise ValueError(
f"{args.key} This should never happen. value was suppose to be reassigned")
In the following case key, value args are automatically assigned to class.
>>> my_class = MyClass(exporter='json', file_name='data.json', loop_count=3)
>>> print(my_class.exporter)
json
>>> print(my_class.file_name)
data.json
>>> print(my_class.loop_count)
3
In the following case my_class.name value is changed from "unknown" to "None" in callback
MyClass._arg_before_cb() method.
>>> my_class = MyClass(exporter='json', file_name='data.json', loop_count=3, name="unknown")
>>> print(my_class.exporter)
json
>>> print(my_class.file_name)
data.json
>>> print(my_class.loop_count)
3
>>> print(my_class.name)
None
In the following case loop_count is a negative number which triggers a CancelEventError
in MyClass._arg_before_cb().
>>> my_class = MyClass(exporter='json', file_name='data.json', loop_count=-1)
kwhelp.CancelEventError: KwargsHelper.auto_assign() canceled in 'BeforeAssignBlindEventArgs'
Note
If KwargsHelper constructor has cancel_error set to False then
no error will be raised when BeforeAssignAutoEventArgs.cancel is set to True.
Callback Usage
Callbacks can be used to hook some of KwargsHelper events.
This class as two callback methods. MyClass._arg_before_cb() method is called before attribute assignment.
MyClass._arg_after_cb() method is called after attribute assignment.
from kwhelp import KwargsHelper, AfterAssignEventArgs, BeforeAssignEventArgs, AssignBuilder
class MyClass:
def __init__(self, **kwargs):
self._loop_count = -1
kw = KwargsHelper(originator=self, obj_kwargs={**kwargs})
ab = AssignBuilder()
kw.add_handler_before_assign(self._arg_before_cb)
kw.add_handler_after_assign(self._arg_after_cb)
ab.append(key='exporter', require=True, types=[str])
ab.append(key='name', require=True, types=[str],
default='unknown')
ab.append(key='file_name', require=True, types=[str])
ab.append(key='loop_count', types=[int],
default=self._loop_count)
result = True
# by default assign will raise errors if conditions are not met.
for arg in ab:
result = kw.assign_helper(arg)
if result == False:
break
if result == False:
raise ValueError("Error parsing kwargs")
def _arg_before_cb(self, helper: KwargsHelper,
args: BeforeAssignEventArgs) -> None:
# callback function before value assigned to attribute
if args.key == 'loop_count' and args.field_value < 0:
# cancel will raise CancelEventError unless
# KwargsHelper constructor has cancel_error=False
args.cancel = True
if args.key == 'name' and args.field_value == 'unknown':
args.field_value = 'None'
def _arg_after_cb(self, helper: KwargsHelper,
args: AfterAssignEventArgs) -> None:
# callback function after value assigned to attribute
if args.key == 'name' and args.field_value == 'unknown':
raise ValueError(
f"{args.key} This should never happen. value was suppose to be reassigned")
@property
def exporter(self) -> str:
return self._exporter
@property
def file_name(self) -> str:
return self._file_name
@property
def name(self) -> str:
return self._name
@property
def loop_count(self) -> int:
return self._loop_count
In the following case my_class.name value is changed from "unknown" to "None" in callback
MyClass._arg_before_cb() method.
>>> my_class = MyClass(exporter='json', file_name='data.json', loop_count=3)
>>> print(my_class.exporter)
json
>>> print(my_class.file_name)
data.json
>>> print(my_class.name)
None
>>> print(my_class.loop_count)
3
In the following case loop_count is a negative number which triggers a CancelEventError
in MyClass._arg_before_cb().
>>> my_class = MyClass(exporter='json', file_name='data.json', loop_count=-1)
kwhelp.CancelEventError: KwargsHelper.assign() canceled in 'BeforeAssignEventArgs'
Note
If KwargsHelper constructor has cancel_error set
to False or KwargsHelper.cancel_error property is set to False then
no error will be raised when BeforeAssignEventArgs.cancel is set to True.
If no error is raised then AfterAssignEventArgs.canceled can be used to check if
an event was canceled in BeforeAssignEventArgs
Basic Usage
Processing **kwargs in a class.
KwargsHelper class assigns attributes to existing class instance if they are missing.
Each key in **kwargs is transformed into an attribute name and that attribute name is assigned to current
instance of class if it does not already exist. Be default attribute names is the key name with _ appended. See Figure 2
**kwargs values are assigned to attribue that match keys.
Use KwargsHelper class to process **kwargs in a class.
from kwhelp import KwargsHelper
class MyClass:
def __init__(self, **kwargs):
kw = KwargsHelper(self, {**kwargs})
kw.auto_assign()
>>> myclass = MyClass(speed=123)
>>> print(myclass._speed)
123
In the following example attribute names are transformed to match the key name.
This is done by setting field_prefix to empty string in constructor.
See Also: KwargsHelper.field_prefix
from kwhelp import KwargsHelper
class MyClass:
def __init__(self, **kwargs):
kw = KwargsHelper(originator=self, obj_kwargs={**kwargs}, field_prefix='')
kw.auto_assign()
>>> myclass = MyClass(speed=123)
>>> print(myclass.speed)
123
See also
KwArg
Auto assign
Auto assign of key, value parirs can be accomplish by calling
KwargsHelper.auto_assign() of KwArg.kwargs_helper property.
from kwhelp import KwArg
def sum_of(**kwargs) -> str:
kw = KwArg(**kwargs)
kw.kwargs_helper.auto_assign(types=[int])
result = 0
for key in kw.kwargs_helper.kw_args:
result = result + kw.__dict__[key]
return result
Assing values of type int.
>>> result = sum_of(first_qtr=199, second_qtr=201)
>>> print(result)
400
Assigning value not of type int results in an error.
>>> result = sum_of(first_qtr=199.78, second_qtr=201)
TypeError: KwArg arg 'first_qtr' is expected to be of '<class 'int'>' but got 'float'
Callback Usage
Callbacks can be used to hook some of KwArg events.
By using the KwArg.kwargs_helper property which is an instance of KwargsHelper it
is possible to use callbacks.
This function has two nested callback functions. arg_before_cb() function is called before
key, value is assigned to KwArg instance. arg_after_cb() function is called after key, value
is assigned to KwArg instance.
from kwhelp import AfterAssignEventArgs, BeforeAssignEventArgs, KwargsHelper, KwArg
def my_method(**kwargs) -> str:
def arg_before_cb(helper: KwargsHelper,
args: BeforeAssignEventArgs) -> None:
# callback function before value assigned to KwArg instance
if args.key == 'msg':
if args.field_value == "cancel":
# cancel will raise CancelEventError unless
# kw.kwargs_helper.cancel_error = False
args.cancel = True
elif args.field_value == "":
args.field_value = "Value:"
if args.key == 'name' and args.field_value == 'unknown':
args.field_value = 'None'
def arg_after_cb(helper: KwargsHelper,
args: AfterAssignEventArgs) -> None:
# callback function after value assigned to KwArg instance
if args.key == 'msg' and args.field_value == "":
raise ValueError(
f"{args.key} This should never happen. value was suppose to be reassigned")
# main function
kw = KwArg(**kwargs)
# assign Callbacks
kw.kwargs_helper.add_handler_before_assign(arg_before_cb)
kw.kwargs_helper.add_handler_after_assign(arg_after_cb)
# assign args
kw.kw_assign(key='first', require=True, types=[int])
kw.kw_assign(key='second', require=True, types=[int])
kw.kw_assign(key='msg', types=[str], default='Result:')
kw.kw_assign(key='end', types=[str])
_result = kw.first + kw.second
if kw.is_attribute_exist('end'):
return_msg = f'{kw.msg} {_result}{kw.end}'
else:
return_msg = f'{kw.msg} {_result}'
return return_msg
Call back does not make changes to the following result.
>>> result = my_method(first = 10, second = 22)
>>> print(result)
Result: 32
Call back changes msg from empty string to Value:
>>> result = my_method(first = 10, second = 22, msg = "")
>>> print(result)
Value: 32
Call back raises CancelEventError when msg equals cancel.
>>> result = my_method(first = 10, second = 22, msg = "cancel")
kwhelp.CancelEventError: KwargsHelper.assign() canceled in 'BeforeAssignEventArgs'
Note
If KwargsHelper.cancel_error property is set to False then
no error will be raised when BeforeAssignEventArgs.cancel is set to True.
If no error is raised then AfterAssignEventArgs.canceled can be used to check if
an event was canceled in BeforeAssignEventArgs
Kw_assign Default Value
Default value can be assigned by adding default args to kw_assign() method.
In the following msg arg is assigned a default of Result:
from kwhelp import KwArg
def my_method(**kwargs) -> str:
kw = KwArg(**kwargs)
# assign args
kw.kw_assign(key='first', require=True, types=[int])
kw.kw_assign(key='second', require=True, types=[int])
kw.kw_assign(key='msg', types=[str], default='Result:')
kw.kw_assign(key='end', types=[str])
_result = kw.first + kw.second
if kw.is_attribute_exist('end'):
return_msg = f'{kw.msg} {_result}{kw.end}'
else:
return_msg = f'{kw.msg} {_result}'
return return_msg
Method result contains prefix of msg default value
>>> result = my_method(first=10, second=22, end="!")
>>> print(result)
Result: 32!
Method result contains Tally as msg default is now overridden by assiging value.
>>> result = my_method(first=10, second=22, end="!", msg="Tally")
>>> print(result)
Tally 32!
Method will raise an error as msg must be of type str as defined by types
>>> result = my_method(first=10, second=22, end="!", msg=-34)
TypeError: KwArg arg 'msg' is expected to be of '<class 'str'>' but got 'int'
Kw_assign field
Field value can be assigned by adding field arg to kw_assign() method.
Sometimes it may be necessary to pass an arg with a name but change it in KwArg instance.
In the following is_key_existing is assigned to is_key_exist of KwArg instance.
This avoids a ReservedAttributeError because is_key_existing is a reserved keyword of KwArg.
from kwhelp import KwArg
def is_key(**kwargs) -> str:
keys = ('one','two', 'four', 'eight')
kw = KwArg(**kwargs)
kw.kw_assign(key='is_key_existing', field='is_key_exist', require=True, types=[str])
if kw.is_key_exist in keys:
return True
return False
>>> result = is_key(is_key_existing="one")
>>> print(result)
True
>>> result = is_key(is_key_existing="three")
>>> print(result)
False
Kw_assign Require Arg
Values can be required by adding require args to kw_assign() method.
In the following first and second args are required
from kwhelp import KwArg
def my_method(**kwargs) -> str:
kw = KwArg(**kwargs)
# assign args
kw.kw_assign(key='first', require=True, types=[int])
kw.kw_assign(key='second', require=True, types=[int])
kw.kw_assign(key='msg', types=[str], default='Result:')
kw.kw_assign(key='end', types=[str])
_result = kw.first + kw.second
if kw.is_attribute_exist('end'):
return_msg = f'{kw.msg} {_result}{kw.end}'
else:
return_msg = f'{kw.msg} {_result}'
return return_msg
first and second are required. msg is not required and has a default value.
end is not required.
>>> result = my_method(first=10, second=22)
>>> print(result)
Result: 32
Output when optional args end and msg are included.
>>> result = my_method(first=10, second=22, end="!", msg="Tally")
>>> print(result)
Tally 32!
Method will raise an error as msg must be of type str as defined by types
>>> result = my_method(first=10)
ValueError: KwArg arg 'second' is required
Kw_assign Rule Checking
Rule checking can be done by adding rules_all or rules_any to kw_assign() method.
Rule checking ensures a value of **kwargs values match rules before assigning to
current instance of class.
All rules
In the following example args first and second must be a positive int with a maximum value of 100.
Arg rules_all of kw_assign() method validates as True only if all IRule match.
Trying to assign any other type or value to first or second results in an error.
Custom Rule for a maximum int value of 100
import kwhelp.rules as rules
class RuleIntMax100(rules.IRule):
def validate(self) -> bool:
if self.field_value > 100:
if self.raise_errors:
raise ValueError(
f"Arg error: '{self.key}' must be equal or less than 100")
return False
return True
from kwhelp import rules, KwArg
def my_method(**kwargs) -> str:
kw = KwArg(**kwargs)
kw.kw_assign(key='first', require=True, rules_all=[
rules.RuleIntPositive,
RuleIntMax100
])
kw.kw_assign(key='second', require=True, rules_all=[
rules.RuleIntPositive,
RuleIntMax100
])
kw.kw_assign(key='msg', types=[str], default='Result:')
kw.kw_assign(key='end', types=[str])
first:int = kw.first
second:int = kw.second
msg: str = kw.msg
_result = first + second
if kw.is_attribute_exist('end'):
return_msg = f'{msg} {_result}{kw.end}'
else:
return_msg = f'{msg} {_result}'
return return_msg
Assign positive int.
>>> result = my_method(first = 10, second = 22)
>>> print(result)
Result: 32
Assign positive int and int greater than 100.
>>> result = my_method(first = 10, second = 122)
kwhelp.exceptions.RuleError: RuleError: Argument: 'second' failed validation.
Rule 'RuleIntMax100' Failed validation.
Expected all of the following rules to match: RuleIntPositive, RuleIntMax100.
Inner Error Message: ValueError: Arg error: 'second' must be equal or less than 100
Assign negative int.
>>> result = my_method(first = -10, second = -22)
kwhelp.exceptions.RuleError: RuleError: Argument: 'first' failed validation.
Rule 'RuleIntPositive' Failed validation.
Expected all of the following rules to match: RuleIntPositive, RuleIntMax100.
Inner Error Message: ValueError: Arg error: 'first' must be a positive int value
Assigning float result is a TypeError
>>> result = my_method(first = 10, second = 22.33)
kwhelp.exceptions.RuleError: RuleError: Argument: 'second' failed validation.
Rule 'RuleIntPositive' Failed validation.
Expected all of the following rules to match: RuleIntPositive, RuleIntMax100.
Inner Error Message: TypeError: Argument Error: 'second' is expecting type of 'int'. Got type of 'float'
Assigning negative int results in a ValueError.
>>> result = my_method(first = 10, second = -5)
kwhelp.exceptions.RuleError: RuleError: Argument: 'second' failed validation.
Rule 'RuleIntPositive' Failed validation.
Expected all of the following rules to match: RuleIntPositive, RuleIntMax100.
Inner Error Message: ValueError: Arg error: 'second' must be a positive int value
Any rule
In the following example args first and second can be a negative or zero float or int zero.
Arg rules_any of kw_assign() method validates as True if any IRule matches.
Trying to assign any other type to first or second results in an error.
from kwhelp import rules, KwArg
def my_method(**kwargs) -> str:
kw = KwArg(**kwargs)
kw.kw_assign(key='first', require=True, rules_any=[
rules.RuleFloatNegativeOrZero,
rules.RuleIntZero
])
kw.kw_assign(key='second', require=True, rules_any=[
rules.RuleFloatNegativeOrZero,
rules.RuleIntZero
])
kw.kw_assign(key='msg', types=[str], default='Result:')
kw.kw_assign(key='end', types=[str])
first:int = kw.first
second:int = kw.second
msg: str = kw.msg
_result = first + second
if kw.is_attribute_exist('end'):
return_msg = f'{msg} {_result}{kw.end}'
else:
return_msg = f'{msg} {_result}'
return return_msg
Assign int zero and float negative.
>>> result = my_method(first = 0, second = -22.5)
>>> print(result)
Result: -22.5
Assign float zero and float negative.
>>> result = my_method(first = 0.0, second = -22.5)
>>> print(result)
Result: -22.5
Assign int zero and float zero.
>>> result = my_method(first = 0, second = 0.0)
>>> print(result)
Result: 0.0
Assign float negative and float negative.
>>> result = my_method(first = -10.8, second = -8.68)
>>> print(result)
Result: -19.48
Assign int and float zero.
>>> result = my_method(first = 12, second = 0.0)
kwhelp.exceptions.RuleError: RuleError: Argument: 'first' failed validation.
Rule 'RuleFloatNegativeOrZero' Failed validation.
Expected at least one of the following rules to match: RuleFloatNegativeOrZero, RuleIntZero.
Inner Error Message: TypeError: Argument Error: 'first' is expecting type of 'float'. Got type of 'int'
Assign float positive and int.
>>> result = my_method(first = 12.46, second = 0)
kwhelp.exceptions.RuleError: RuleError: Argument: 'first' failed validation.
Rule 'RuleFloatNegativeOrZero' Failed validation.
Expected at least one of the following rules to match: RuleFloatNegativeOrZero, RuleIntZero.
Inner Error Message: ValueError: Arg error: 'first' must be equal to 0.0 or a negative float value
Assign float negative and float positive.
>>> result = my_method(first = -12.46, second = 1.2)
kwhelp.exceptions.RuleError: RuleError: Argument: 'second' failed validation.
Rule 'RuleFloatNegativeOrZero' Failed validation.
Expected at least one of the following rules to match: RuleFloatNegativeOrZero, RuleIntZero.
Inner Error Message: ValueError: Arg error: 'second' must be equal to 0.0 or a negative float value
Assigning a str results in an error.
>>> result = my_method(first=-10.5, second="0")
kwhelp.exceptions.RuleError: RuleError: Argument: 'second' failed validation.
Rule 'RuleFloatNegativeOrZero' Failed validation.
Expected at least one of the following rules to match: RuleFloatNegativeOrZero, RuleIntZero.
Inner Error Message: TypeError: Argument Error: 'second' is expecting type of 'float'. Got type of 'str'
Included Rules
Kw_assign Type Checking
Type checking can be done by adding types to kw_assign() method.
Type checking ensures the type of **kwargs values that are assigned to attributes of current instance of class.
from kwhelp import KwArg
def speed_msg(**kwargs) -> str:
kw = KwArg(**kwargs)
kw.kw_assign(key="speed", require=True, types=[int, float])
if kw.speed > 100:
msg = f"Speed of '{kw.speed}' is fast. Caution recommended."
elif kw.speed < -40:
msg = f"Reverse speed of '{kw.speed}' is fast. Caution recommended."
elif kw.speed < 0:
msg = f"Reverse speed of '{kw.speed}'. Normal operations."
else:
msg = f"speed of '{kw.speed}'. Normal operations."
return msg
speed_msg float value.
>>> result = speed_msg(speed = 35.8)
>>> print(result)
speed of '35.8'. Normal operations.
speed_msg float fast value.
>>> result = speed_msg(speed = 227.59)
>>> print(result)
Speed of '227.59' is fast. Caution recommended.
speed_msg int value.
>>> result = speed_msg(speed = -43)
>>> print(result)
Reverse speed of '-43' is fast. Caution recommended.
speed_msg no params.
>>> result = speed_msg()
ValueError: KwArg arg 'speed' is required
speed_msg wrong type.
>>> result = speed_msg(speed = "Fast")
TypeError: KwArg arg 'speed' is expected to be of '<class 'float'> | <class 'int'>' but got 'str'
Decorators
Decorators can be used to validate functions.
Decorator Index
AcceptedTypes Usage
AcceptedTypes Decorator that decorates methods that requires
args to match types specificed.
Includes features:
The following example requres:
oneis of typeint
twois of typefloatorint
threeis of typestr.
from kwhelp.decorator import AcceptedTypes
@AcceptedTypes(int, (float, int), str)
def foo(one, two, three):
result = [one, two, three]
return result
>>> result = foo(1, 2.2, "Hello")
>>> print(result)
[1, 2.2, 'Hello']
>>> result = foo(1, "2.2", "Hello")
>>> print(result)
TypeError: Arg 'two' in 2nd position is expected to be of 'float' or 'int' but got 'str'.
AcceptedTypes decorator error.
*args*args can be used a parameters. When using *args with AcceptedTypes the
total number of args for the function must match the number of types passed into AcceptedTypes.
from kwhelp.decorator import AcceptedTypes
@AcceptedTypes(int, (float, int), int, (int, str), int)
def foo(one, two, three, *args):
result = [one, two, three]
for arg in args:
result.append(arg)
return result
All value of type int
>>> result = foo(1, 2, 3, 4, 5)
>>> print(result)
[1, 2, 3, 4, 5]
Alternative type for args that support them.
>>> result = foo(1, 2.77, 3, "Red", 5)
>>> print(result)
[1, 2.77, 3, 'Red', 5]
Last arg is not of type int and raised an error
>>> result = foo(1, 2, 3, 4, 5.766)
TypeError: Arg in 5th position of is expected to be of 'int' but got 'float'.
AcceptedTypes decorator error.
Too many args passed into Function result in an error
>>> result = foo(1, 2, 3, 4, 5, 1000)
ValueError: Invalid number of arguments for foo()
AcceptedTypes decorator error.
**kwargs**kwargs can be used a parameters. When using *args with AcceptedTypes the
total number of args for the function must match the number of types passed into AcceptedTypes.
@AcceptedTypes(int, (float, int), int, (int, str), int)
def foo(one, *args, **kwargs):
result_args = [*args]
result_args.insert(0, one)
result_dic = {**kwargs}
return result_args, result_dic
All int values with last arg as key, value.
>>> result = foo(1, 2, 3, 4, last=5)
>>> print(result)
([1, 2, 3, 4], {'last': 5})
>>> result = foo(1, 2, 3, 4, last=5, exceeded=None)
ValueError: Invalid number of arguments for foo()
AcceptedTypes decorator error.
AcceptedTypes can be applied to class methods.
When appling to class method set the ftype arg to match DecFuncEnum.
Class method applying to constructor.
from kwhelp.decorator import AcceptedTypes, DecFuncEnum
class Foo:
@AcceptedTypes((int, float), (int, float), ftype=DecFuncEnum.METHOD)
def __init__(self, start, stop):
self.start = start
self.stop = stop
>>> f = Foo(1, 99.9)
>>> print(f.start, f.stop)
1 99.9
>>> f = Foo(1, None)
TypeError: Arg 'stop' in 2nd position is expected to be of 'int' or 'float' but got 'NoneType'.
AcceptedTypes decorator error.
AcceptedTypes can be use on static method of a class as well by
setting ftype to DecFuncEnum METHOD_STATIC option.
from kwhelp.decorator import AcceptedTypes, DecFuncEnum, ReturnType
class Foo:
@staticmethod
@AcceptedTypes(int, int, ftype=DecFuncEnum.METHOD_STATIC)
@ReturnType(int)
def add(first, last):
return first + last
>>> print(Foo.add(34, 76))
110
>>> print(Foo.add(7.2, 76))
TypeError: Arg 'first' in 1st position is expected to be of 'int' but got 'float'.
AcceptedTypes decorator error.
AcceptedTypes can be use on class method of a class as well by
setting ftype to DecFuncEnum METHOD_CLASS option.
from kwhelp.decorator import AcceptedTypes, DecFuncEnum, ReturnType
class Foo:
@classmethod
@AcceptedTypes(int, int, ftype=DecFuncEnum.METHOD_CLASS)
@ReturnType(int)
def add(cls, first, last):
return first + last
>>> print(Foo.add(34, 76))
110
>>> print(Foo.add(7.2, 76))
TypeError: Arg 'first' in 1st position is expected to be of 'int' but got 'float'.
AcceptedTypes decorator error.
opt_all_args argument allows the last class type passed into AcceptedTypes to
validate all remaining arguments of wrapped function.
For more examples see opt_all_args.
@AcceptedTypes(float, (float, int), opt_all_args=True)
def sum_num(*args):
return sum(args)
The first arg of sum_num must be a float. Remaining args can be float or int.
>>> print(sum_num(1.3, 44.556, 10, 22, 45, 7.88))
130.736
>>> print(sum_num(1, 44.556, 10, 22, 45, 7.88))
TypeError: Arg in 1st position of is expected to be of 'float' but got 'int'.
AcceptedTypes decorator error.
>>> print(sum_num(1.3, 44.556, 10, 22, 45, 7.88, "77"))
TypeError: Arg in 7th position of is expected to be of 'float' or 'int' but got 'str'.
AcceptedTypes decorator error.
The arguments are validated by AcceptedTypes can be filtered by setting opt_args_filter option.
For more examples see opt_args_filter.
In the following example all *args must of of type float or int.
opt_args_filter=DecArgEnum.ARGS filters AcceptedTypes to only process *args.
from kwhelp.decorator import AcceptedTypes, DecArgEnum
@AcceptedTypes((float, int), opt_all_args=True, opt_args_filter=DecArgEnum.ARGS)
def sum_num(*args, msg: str):
_sum = sum(args)
return msg + str(_sum)
>>> result = sum_num(1, 2, 3, 4, 5, 6, msg='Total: ')
>>> print(result)
Total: 21
AcceptedTypes can be combined with other decorators.
The following example limits how many args are allowed by applying
ArgsMinMax decorator.
from kwhelp.decorator import AcceptedTypes, ArgsMinMax
@ArgsMinMax(max=6)
@AcceptedTypes(float, (float, int), opt_all_args=True)
def sum_num(*args):
return sum(args)
>>> print(sum_num(1.3, 44.556, 10, 22, 45, 7.88))
130.736
>>> print(sum_num(1, 44.556, 10, 22, 45, 7.88, 100))
ValueError: Invalid number of args pass into 'sum_num'.
Expected max of '6'. Got '7' args.
ArgsMinMax decorator error.
Multiple AcceptedTypes can be applied to a single function.
from kwhelp.decorator import AcceptedTypes, DecArgEnum
@AcceptedTypes(str, opt_all_args=True, opt_args_filter=DecArgEnum.ARGS)
@AcceptedTypes((int, float), opt_all_args=True, opt_args_filter=DecArgEnum.NO_ARGS)
def foo(*args, first, last=1001, **kwargs):
return [*args] + [first, last] + [v for _, v in kwargs.items()]
>>> result = foo("a", "b", "c", first=-100, one=101.11, two=22.22, third=33.33)
>>> print(result)
['a', 'b', 'c', -100, 1001, 101.11, 22.22, 33.33]
>>> result = foo("a", "b", 1, first=-100, one=101.11, two=22.22, third=33.33)
TypeError: Arg in 3rd position of is expected to be of 'str' but got 'int'.
AcceptedTypes decorator error.
>>> result = foo("a", "b", "c", first=-100, one=101.11, two="2nd", third=33.33)
TypeError: Arg 'two' in 4th position is expected to be of 'float' or 'int' but got 'str'.
AcceptedTypes decorator error.
ArgsLen Usage
ArgsLen decorartor that sets the number of args that can be added to a function.
Includes features:
Decorator can be applied with a single set Length. In the following example
if anything other than 3 args are passed into foo a ValueError will be raised
from kwhelp.decorator import ArgsLen
@ArgsLen(3)
def foo(*args):
return len(args)
Passing in three arg values works as expected.
>>> result = foo("a", "b", "c")
>>> print(result)
3
Passing in two args when three are expected raises a ValueError
>>> result = foo("a", "b")
ValueError: Invalid number of args pass into 'foo'.
Expected Length: '3'. Got '4' args.
ArgsLen decorator error.
It is possible to allow more then one length to function by passing in multilple int values to decorator.
from kwhelp.decorator import ArgsLen
@ArgsLen(3, 5)
def foo(*args):
return len(args)
Passing in 3 args.
>>> result = foo("a", "b", "c")
>>> print(result)
3
Passing in 5 args.
>>> result = foo("a", "b", "c", "d", "e")
>>> print(result)
5
Passing in 4 args result in a ValueError.
>>> result = foo("a", "b", "c", "d")
ValueError: Invalid number of args pass into 'foo'.
Expected Lengths: '3' or '5'. Got '4' args.
ArgsLen decorator error.
It is possible to allow more then one length to function by passing in
pairs of int values in the form of iterable values such as list or tuple values to decorator.
The following example allows 3, 4, 5, 7, 8, 9 args.
Note that 1, 2, 6 or greater than 9 args will result in a ValueError.
from kwhelp.decorator import ArgsLen
@ArgsLen((3, 5), (7, 9))
def foo(*args):
return len(args)
Passing in 3 args.
>>> result = foo("a", "b", "c")
>>> print(result)
3
Passing in 8 args.
from kwhelp.decorator import ArgsLen
>>> result = foo("a", "b", "c", "d", "e", "f", "g", "h")
>>> print(result)
8
Passing in 6 args.
>>> result = foo("a", "b", "c", "d", "e", "f")
ValueError: Invalid number of args pass into 'foo'.
Expected Ranges: (3, 5) or (7, 9). Got '6' args.
ArgsLen decorator error.
Ranges and lengths can be combined when needed.
The following example allows 3, 4, 5, 7, 8, 9 args.
Note that 1, 2, 6 or greater than 9 args will result in a ValueError.
from kwhelp.decorator import ArgsLen
@ArgsLen(3, 4, 5, (7, 9))
def foo(*args):
return len(args)
Passing in 3 args.
>>> result = foo("a", "b", "c")
>>> print(result)
3
Passing in 8 args.
>>> result = foo("a", "b", "c", "d", "e", "f", "g", "h")
>>> print(result)
8
Passing in 6 args.
>>> result = foo("a", "b", "c", "d", "e", "f")
ValueError: Invalid number of args pass into 'foo'.
Expected Lengths: '3', '4', or '5'. Expected Range: (7, 9). Got '6' args.
ArgsLen decorator error.
Decorator can be used on class methods by setting ftype arg. to a value of
DecFuncEnum.
from kwhelp.decorator import ArgsLen
class Foo:
@ArgsLen(0, (2, 4), ftype=DecFuncEnum.METHOD)
def __init__(self, *args): pass
@ArgsLen(3, 5, ftype=DecFuncEnum.METHOD)
def bar(self, *args): pass
from kwhelp.decorator import ArgsLen
class Foo:
@staticmethod
@ArgsLen(3, 5, ftype=DecFuncEnum.METHOD_STATIC)
def bar(self, *args): pass
from kwhelp.decorator import ArgsLen
class Foo:
@staticmethod
@ArgsLen(3, 5, ftype=DecFuncEnum.METHOD_CLASS)
def bar(self, *args): pass
ArgsMinMax Usage
ArgsMinMax decorartor that sets the min and/or max number of args that can be added to a function.
Includes features:
Decorator can be applied with a min Length. In the following example
if less than 3 args are passed into foo a ValueError will be raised
from kwhelp.decorator import ArgsMinMax
@ArgsMinMax(min=3)
def foo(*args):
return len(args)
Passing in three arg values works as expected.
>>> result = foo("a", "b", "c")
>>> print(result)
3
Passing in two args when three are expected raises a ValueError
>>> result = foo("a", "b")
ValueError: Invalid number of args pass into 'foo'.
Expected min of '3'. Got '2' args.
ArgsMinMax decorator error.
It is possible to set min and max allowed arguments.
from kwhelp.decorator import ArgsMinMax
@ArgsMinMax(min=3, max=5)
def foo(*args):
return len(args)
Passing in 3 args.
>>> result = foo("a", "b", "c")
>>> print(result)
3
Passing in 5 args.
>>> result = foo("a", "b", "c", "d", "e")
>>> print(result)
5
Passing in 6 args result in a ValueError.
>>> result = foo("a", "b", "c", "d", "e", "f")
ValueError: Invalid number of args pass into 'foo'.
Expected min of '3'. Expected max of '5'. Got '6' args.
ArgsMinMax decorator error.
Decorator can be used on class methods by setting ftype arg. to a value of
DecFuncEnum.
from kwhelp.decorator import ArgsMinMax
class Foo:
@ArgsMinMax(max=6, ftype=DecFuncEnum.METHOD)
def __init__(self, *args): pass
@ArgsMinMax(3, 5, ftype=DecFuncEnum.METHOD)
def bar(self, *args): pass
from kwhelp.decorator import ArgsMinMax
class Foo:
@staticmethod
@ArgsMinMax(min=3 max=5, ftype=DecFuncEnum.METHOD_STATIC)
def bar(self, *args): pass
from kwhelp.decorator import ArgsMinMax
class Foo:
@staticmethod
@ArgsMinMax(min=3 max=5, ftype=DecFuncEnum.METHOD_CLASS)
def bar(self, *args): pass
DefaultArgs Usage
DefaultArgs decorator that defines default values for **kwargs of a function.
from kwhelp.decorator import DefaultArgs
@DefaultArgs(speed=45, limit=60, name="John")
def speed_msg(**kwargs) -> str:
name = kwargs.get('name')
limit = kwargs.get('limit')
speed = kwargs.get('speed')
if limit > speed:
msg = f"Current speed is '{speed}'. {name} may go faster as the limit is '{limit}'."
elif speed == limit:
msg = f"Current speed is '{speed}'. {name} are at the limit."
else:
msg = f"Please slow down limit is '{limit}' and current speed is '{speed}'."
if 'hours' in kwargs:
msg = msg + f" Current driving hours is '{kwargs['hours']}'."
return msg
>>> result = speed_msg()
>>> print(result)
Current speed is '45'. John may go faster as the limit is '60'.
>>> result = speed_msg(name="Sue", speed=47)
>>> print(result)
Current speed is '47'. Sue may go faster as the limit is '60'.
RequireArgs Usage
RequireArgs decorator defines required args for **kwargs of a function.
Includes features:
from kwhelp.decorator import TypeCheckKw, RequireArgs
@RequireArgs("speed", "limit", "name")
@TypeCheckKw(arg_info={"speed": 0, "limit": 0, "hours": 0, "name": 1},
types=[(int, float), str])
def speed_msg(**kwargs) -> str:
name = kwargs.get('name')
limit = kwargs.get('limit')
speed = kwargs.get('speed')
if limit > speed:
msg = f"Current speed is '{speed}'. {name} may go faster as the limit is '{limit}'."
elif speed == limit:
msg = f"Current speed is '{speed}'. {name} are at the limit."
else:
msg = f"Please slow down limit is '{limit}' and current speed is '{speed}'."
if 'hours' in kwargs:
msg = msg + f" Current driving hours is '{kwargs['hours']}'."
return msg
>>> result = speed_msg(speed=45, limit=60, name="John")
>>> print(result)
Current speed is '45'. John may go faster as the limit is '60'.
>>> result = speed_msg(speed=45, limit=60)
>>> print(result)
ValueError: 'name' is a required arg.
>>> result = speed_msg(speed="Fast", limit=60, name="John")
>>> print(result)
TypeError: Arg 'speed' is expected to be of '<class 'int'> | <class 'float'>' but got 'str'
ReturnRuleAll usage
ReturnRuleAll decorator that decorates methods that require return value to match all of the rules specificed.
Includes features:
In the following example return value must be an int or a negative float value.
from kwhelp.decorator import ReturnRuleAll
from kwhelp import rules
@ReturnRuleAll(rules.RuleIntPositive)
def req_test(*arg):
return sum(arg)
>>> result = req_test(2, 4)
>>> print(result)
6
Argument of float raised error.
>>> result = req_test(2, 2.4)
kwhelp.exceptions.RuleError: RuleError: 'req_test' error. Argument: 'return' failed validation.
Rule 'RuleIntPositive' Failed validation.
Expected the following rule to match: RuleIntPositive.
Inner Error Message: TypeError: Argument Error: 'return' is expecting type of 'int'. Got type of 'float'
Negative return value raises error.
>>> result = req_test(2, -3)
kwhelp.exceptions.RuleError: RuleError: 'req_test' error. Argument: 'return' failed validation.
Rule 'RuleIntPositive' Failed validation.
Expected the following rule to match: RuleIntPositive.
Inner Error Message: ValueError: Arg error: 'return' must be a positive int value
In the following example ReturnRuleAll is applied to a class method.
Note that ftype arg is set to DecFuncEnum.METHOD for class methods.
from kwhelp.decorator import ReturnRuleAll
from kwhelp import rules
class T:
@ReturnRuleAll(rules.RuleIntPositive, ftype=DecFuncEnum.METHOD)
def req_test(self, *arg):
return sum(arg)
>>> t = T()
>>> result = t.req_test(2, 4)
>>> print(result)
6
Argument of float raised error.
>>> t = T()
>>> result = t.req_test(2, 2.5)
kwhelp.exceptions.RuleError: RuleError: 'req_test' error. Argument: 'return' failed validation.
Rule 'RuleIntPositive' Failed validation.
Expected the following rule to match: RuleIntPositive.
Inner Error Message: TypeError: Argument Error: 'return' is expecting type of 'int'. Got type of 'float'
Negative return value raises error.
>>> t = T()
>>> result = t.req_test(2, -3)
kwhelp.exceptions.RuleError: RuleError: 'req_test' error. Argument: 'return' failed validation.
Rule 'RuleIntPositive' Failed validation.
Expected the following rule to match: RuleIntPositive.
Inner Error Message: ValueError: Arg error: 'return' must be a positive int value
ReturnRuleAny Usage
ReturnRuleAny decorator that decorates methods that require return value to match at least one of the rules specificed.
Includes features:
In the following example return value must be an int or a negative float value.
from kwhelp.decorator import ReturnRuleAny
from kwhelp import rules
@ReturnRuleAny(rules.RuleInt, rules.RuleFloatNegative)
def req_test(*arg):
return sum(arg)
Postiive return int value is valid
>>> result = req_test(2, 4)
>>> print(result)
6
Negative return float value is valid
>>> result = req_test(2, -5.2)
>>> print(result)
-3.2
Positive return float value raised error.
>>> result = req_test(2, 2.4)
kwhelp.exceptions.RuleError: RuleError: 'req_test' error. Argument: 'return' failed validation.
Rule 'RuleInt' Failed validation.
Expected at least one of the following rules to match: RuleInt, RuleFloatNegative.
Inner Error Message: TypeError: Argument Error: 'return' is expecting type of 'int'. Got type of 'float'
In the following example ReturnRuleAny is applied to a class method.
Note that ftype arg is set to DecFuncEnum.METHOD for class methods.
from kwhelp.decorator import ReturnRuleAny
from kwhelp import rules
class T:
@ReturnRuleAny(rules.RuleInt, rules.RuleFloatNegative, ftype=DecFuncEnum.METHOD)
def req_test(self, *arg):
return sum(arg)
>>> t = T()
>>> result = t.req_test(2, 4)
>>> print(result)
6
Returning a postitive float result in an error.
>>> t = T()
>>> result = t.req_test(2, 2.5)
kwhelp.exceptions.RuleError: RuleError: 'req_test' error. Argument: 'return' failed validation.
Rule 'RuleInt' Failed validation.
Expected at least one of the following rules to match: RuleInt, RuleFloatNegative.
Inner Error Message: TypeError: Argument Error: 'return' is expecting type of 'int'. Got type of 'float'
ReturnType Usage
ReturnType decorator reqires that return matches type.
Includes features:
The following example requres return type of str by applying ReturnType
decorator with parameter of str.
from kwhelp.decorator import ReturnType
@ReturnType(str)
def foo(*args):
result = None
for i, arg in enumerate(args):
if i == 0:
result = arg
else:
result = result + ", " + arg
return result
Result when type of str is returned.
>>> result = foo("Hello", "World", "Happy", "Day")
>>> print(result)
Hello, World, Happy, Day
Error is raises when retrun type is not valid.
>>> result = foo(2)
TypeError: Return Value is expected to be of 'str' but got 'int'.
ReturnType decorator error.
ReturnType can accept multiple return types.
In the following example return type must be int or str.
from kwhelp.decorator import ReturnType
@ReturnType(int, str)
def ret_test(start, length, end):
result = start + length + end
return result
>>> result = ret_test(2, 4, 6)
>>> print(result)
12
>>> result = ret_test("In the beginning ", "and forever more, ", "time is everlasting.")
>>> print(result)
In the beginning and forever more, time is everlasting.
>>> result = ret_test(1.33, 4, 6)
TypeError: Return Value is expected to be of 'int' or 'str' but got 'float'.
ReturnType decorator error.
RuleCheckAll Usage
RuleCheckAll decorator reqires that each args of a function match all rules specified.
Includes features:
*argsThis example requires that all args positive int
from kwhelp.decorator import RuleCheckAll
import kwhelp.rules as rules
@RuleCheckAll(rules.RuleIntPositive)
def add_positives(*args) -> float:
result = 0
for arg in args:
result += arg
return result
Adding positive numbers works as expected.
>>> result = add_positives(1, 4, 6, 3, 10)
>>> print(result)
24
Because decorator rules dictate that only postiive numbers are allowed. A negative number will raise an error.
>>> result = add_positives(2, 1, -1)
kwhelp.exceptions.RuleError: RuleError: 'add_positives' error.
Rule 'RuleIntPositive' Failed validation.
Expected the following rule to match: RuleIntPositive.
RuleCheckAll decorator error.
Inner Error Message: ValueError: Arg error: 'arg' must be a positive int value
Rules dictate that if a type is not int then an error will be raised.
>>> result = add_positives(2, 1, 3.55)
kwhelp.exceptions.RuleError: RuleError: 'add_positives' error.
Rule 'RuleIntPositive' Failed validation.
Expected the following rule to match: RuleIntPositive.
RuleCheckAll decorator error.
Inner Error Message: TypeError: Argument Error: 'arg' is expecting type of 'int'. Got type of 'float'
This example requires that all args positive int.
from kwhelp.decorator import RuleCheckAll
import kwhelp.rules as rules
@RuleCheckAll(rules.RuleIntPositive)
def speed_msg(speed, limit, **kwargs) -> str:
if limit > speed:
msg = f"Current speed is '{speed}'. You may go faster as the limit is '{limit}'."
elif speed == limit:
msg = f"Current speed is '{speed}'. You are at the limit."
else:
msg = f"Please slow down limit is '{limit}' and you are currenlty going '{speed}'."
if 'hours' in kwargs:
msg = msg + f" Current driving hours is '{kwargs['hours']}'."
return msg
Adding positive numbers works as expected.
>>> result = speed_msg(speed=45, limit=60)
>>> print(result)
Current speed is '45'. You may go faster as the limit is '60'.
>>> result = speed_msg(speed=66, limit=60, hours=3)
>>> print(result)
Please slow down limit is '60' and you are currenlty going '66'. Current driving hours is '3'.
Because decorator rules dictate that only postiive numbers are allowed. A negative number will raise an error.
>>> result = speed_msg(speed=-2, limit=60)
kwhelp.exceptions.RuleError: RuleError: 'speed_msg' error. Argument: 'speed' failed validation.
Rule 'RuleIntPositive' Failed validation.
Expected the following rule to match: RuleIntPositive.
RuleCheckAll decorator error.
Inner Error Message: ValueError: Arg error: 'speed' must be a positive int value
>>> result = speed_msg(speed=66, limit=60, hours=-2)
kwhelp.exceptions.RuleError: RuleError: 'speed_msg' error. Argument: 'hours' failed validation.
Rule 'RuleIntPositive' Failed validation.
Expected the following rule to match: RuleIntPositive.
RuleCheckAll decorator error.
Inner Error Message: ValueError: Arg error: 'hours' must be a positive int value
Rules dictate that if a type is not int then an error will be raised.
>>> result = speed_msg(speed=45, limit="Fast")
kwhelp.exceptions.RuleError: RuleError: 'speed_msg' error. Argument: 'limit' failed validation.
Rule 'RuleIntPositive' Failed validation.
Expected the following rule to match: RuleIntPositive.
RuleCheckAll decorator error.
Inner Error Message: TypeError: Argument Error: 'limit' is expecting type of 'int'. Got type of 'str'
The arguments are validated by RuleCheckAll can be filtered by setting opt_args_filter option.
For more examples see opt_args_filter.
In the following example all *args must be positive int.
opt_args_filter=DecArgEnum.ARGS filters RuleCheckAll to only process *args.
from kwhelp.decorator import RuleCheckAll, DecArgEnum
from kwhelp import rules
@RuleCheckAll(rules.RuleIntPositive, opt_args_filter=DecArgEnum.ARGS)
def foo(*args, first, last="!", **kwargs):
return [*args] + [first, last] + [v for _, v in kwargs.items()]
>>> result = foo(101, 223, 778, 887, first="1st", one='one', two="2nd")
>>> print(result)
[101, 223, 778, 887, '1st', '!', 'one', '2nd']
>>> result = foo(101, 223, -778, 887, first="1st", one='one', two="2nd")
kwhelp.exceptions.RuleError: RuleError: 'foo' error.
Rule 'RuleIntPositive' Failed validation.
Expected the following rule to match: RuleIntPositive.
RuleCheckAll decorator error.
Inner Error Message: ValueError: Arg error: 'arg' must be a positive int value
RuleCheckAllKw Usage
RuleCheckAllKw decorator allows each arg of a function match all rules specified.
Each arg can have seperate rules applied.
Includes features:
RuleCheckAllKw constructor args arg_info and rules work together.
arg_info is a dictionary with a key of str that matches an arg name of the function that
is being decorated.
arg_info value is one of the following:
intis an index of an item inrules
IRulea rule to match
Iterator[IRule]a list of rules to match
arg_info can be mixed.
rules is a list of rules to match. Each element is an IRule or a list of IRule.
Custom IRule class that limits value to a max int value of 100.
import kwhelp.rules as rules
class RuleIntMax100(rules.IRule):
def validate(self) -> bool:
if self.field_value > 100:
if self.raise_errors:
raise ValueError(
f"Arg error: '{self.key}' must be equal or less than 100")
return False
return True
RuleCheckAllKw decorated function.
from kwhelp.decorator import RuleCheckAllKw
import kwhelp.rules as rules
@RuleCheckAllKw(arg_info={"speed": 0, "limit": 1, "hours": 1, "name": 2},
rules=[rules.RuleIntPositive,
(rules.RuleIntPositive, RuleIntMax100),
rules.RuleStrNotNullEmptyWs])
def speed_msg(speed, limit, **kwargs) -> str:
name = kwargs.get('name', 'You')
if limit > speed:
msg = f"Current speed is '{speed}'. {name} may go faster as the limit is '{limit}'."
elif speed == limit:
msg = f"Current speed is '{speed}'. {name} are at the limit."
else:
msg = f"Please slow down limit is '{limit}' and current speed is '{speed}'."
if 'hours' in kwargs:
msg = msg + f" Current driving hours is '{kwargs['hours']}'."
return msg
>>> result = speed_msg(speed=45, limit=60)
>>> print(result)
Current speed is '45'. You may go faster as the limit is '60'.
>>> result = speed_msg(speed=45, limit=60, name="John")
>>> print(result)
Current speed is '45'. John may go faster as the limit is '60'.
>>> result = speed_msg(speed=66, limit=60, hours=3, name="John")
>>> print(result)
Please slow down limit is '60' and current speed is '66'. Current driving hours is '3'.
If any rule fails validation then a RuleError is raised.
>>> result = speed_msg(speed=-2, limit=60)
kwhelp.exceptions.RuleError: RuleError: 'speed_msg' error. Argument: 'speed' failed validation.
Rule 'RuleIntPositive' Failed validation.
Expected the following rule to match: RuleIntPositive.
RuleCheckAllKw decorator error.
Inner Error Message: ValueError: Arg error: 'speed' must be a positive int value
>>> result = speed_msg(speed=66, limit=60, name=" ")
kwhelp.exceptions.RuleError: RuleError: 'speed_msg' error. Argument: 'name' failed validation.
Rule 'RuleStrNotNullEmptyWs' Failed validation.
Expected the following rule to match: RuleStrNotNullEmptyWs.
RuleCheckAllKw decorator error.
Inner Error Message: ValueError: Arg error: 'name' must not be empty or whitespace str
speed_msg decorated with a mixed arg_info with IRule instance and index to rules.
from kwhelp.decorator import RuleCheckAllKw
import kwhelp.rules as rules
@RuleCheckAllKw(arg_info={"speed": rules.RuleIntPositive, "limit": 0,
"hours": 0, "name": rules.RuleStrNotNullEmptyWs},
rules=[(rules.RuleIntPositive, RuleIntMax100)])
def speed_msg(speed, limit, **kwargs) -> str:
name = kwargs.get('name', 'You')
if limit > speed:
msg = f"Current speed is '{speed}'. {name} may go faster as the limit is '{limit}'."
elif speed == limit:
msg = f"Current speed is '{speed}'. {name} are at the limit."
else:
msg = f"Please slow down limit is '{limit}' and current speed is '{speed}'."
if 'hours' in kwargs:
msg = msg + f" Current driving hours is '{kwargs['hours']}'."
return msg
RuleCheckAny Usage
RuleCheckAny decorator reqires that each args of a function match one or more rules.
Includes features:
*argsThis example requires that all args positive int or positive float.
from kwhelp.decorator import RuleCheckAny
import kwhelp.rules as rules
@RuleCheckAny(rules.RuleIntPositive, rules.RuleFloatPositive)
def add_positives(*args) -> float:
result = 0.0
for arg in args:
result += float(arg)
return result
Adding positive numbers works as expected.
>>> result = add_positives(1, 4, 6.9, 3.9, 7.3)
>>> print(result)
23.1
Because decorator rules dictate that only postiive numbers are allowed. A negative number will raise an error.
>>> result = add_positives(2, 1.2, -1)
kwhelp.exceptions.RuleError: RuleError: 'add_positives' error.
Rule 'RuleIntPositive' Failed validation.
Expected at least one of the following rules to match: RuleIntPositive, RuleFloatPositive.
RuleCheckAny decorator error.
Inner Error Message: ValueError: Arg error: 'arg' must be a positive int value
Rules dictate that if a type is not int or float then an error will be raised.
>>> result = add_positives(2, 1.2, "4")
kwhelp.exceptions.RuleError: RuleError: 'add_positives' error.
Rule 'RuleIntPositive' Failed validation.
Expected at least one of the following rules to match: RuleIntPositive, RuleFloatPositive.
RuleCheckAny decorator error.
Inner Error Message: TypeError: Argument Error: 'arg' is expecting type of 'int'. Got type of 'str'
This example requires that all args are positive int or positive float.
from kwhelp.decorator import RuleCheckAny
import kwhelp.rules as rules
@RuleCheckAny(rules.RuleIntPositive, rules.RuleFloatPositive)
def speed_msg(speed, limit, **kwargs) -> str:
if limit > speed:
msg = f"Current speed is '{speed}'. You may go faster as the limit is '{limit}'."
elif speed == limit:
msg = f"Current speed is '{speed}'. You are at the limit."
else:
msg = f"Please slow down limit is '{limit}' and you are currenlty going '{speed}'."
if 'hours' in kwargs:
msg = msg + f" Current driving hours is '{kwargs['hours']}'"
return msg
Adding positive numbers works as expected.
>>> result = speed_msg(speed=45, limit=60)
>>> print(result)
Current speed is '45'. You may go faster as the limit is '60'.
>>> result = speed_msg(speed=66, limit=60, hours=4.7)
>>> print(result)
Please slow down limit is '60' and you are currenlty going '66'. Current driving hours is '4.7
Because decorator rules dictate that only postiive numbers are allowed. A negative number will raise an error.
>>> result = speed_msg(speed=-2, limit=60)
kwhelp.exceptions.RuleError: RuleError: 'speed_msg' error. Argument: 'speed' failed validation.
Rule 'RuleIntPositive' Failed validation.
Expected at least one of the following rules to match: RuleIntPositive, RuleFloatPositive.
RuleCheckAny decorator error.
Inner Error Message: ValueError: Arg error: 'speed' must be a positive int value
>>> result = speed_msg(speed=66, limit=60, hours=-0.2)
kwhelp.exceptions.RuleError: RuleError: 'speed_msg' error. Argument: 'hours' failed validation.
Rule 'RuleIntPositive' Failed validation.
Expected at least one of the following rules to match: RuleIntPositive, RuleFloatPositive.
RuleCheckAny decorator error.
Inner Error Message: TypeError: Argument Error: 'hours' is expecting type of 'int'. Got type of 'float'
Rules dictate that if a type is not int or float then an error will be raised.
>>> result = speed_msg(speed=45, limit="Fast")
kwhelp.exceptions.RuleError: RuleError: 'speed_msg' error. Argument: 'limit' failed validation.
Rule 'RuleIntPositive' Failed validation.
Expected at least one of the following rules to match: RuleIntPositive, RuleFloatPositive.
RuleCheckAny decorator error.
Inner Error Message: TypeError: Argument Error: 'limit' is expecting type of 'int'. Got type of 'str'
The arguments are validated by RuleCheckAny can be filtered by setting opt_args_filter option.
For more examples see opt_args_filter.
In the following example all *args must be positive int or postive float.
opt_args_filter=DecArgEnum.ARGS filters RuleCheckAll to only process *args.
from kwhelp.decorator import RuleCheckAny, DecArgEnum
from kwhelp import rules
@RuleCheckAny(rules.RuleIntPositive, rules.RuleFloatPositive, opt_args_filter=DecArgEnum.ARGS)
def foo(*args, first, last="!", **kwargs):
return [*args] + [first, last] + [v for _, v in kwargs.items()]
>>> result = foo(101.11, 223.77, 778, 887, first="1st", one='one', two="2nd")
>>> print(result)
[101.11, 223.77, 778, 887, '1st', '!', 'one', '2nd']
>>> result = foo(101.11, -223.77, 778, 887, first="1st", one='one', two="2nd")
kwhelp.exceptions.RuleError: RuleError: 'foo' error.
Rule 'RuleIntPositive' Failed validation.
Expected at least one of the following rules to match: RuleIntPositive, RuleFloatPositive.
RuleCheckAny decorator error.
Inner Error Message: TypeError: Argument Error: 'arg' is expecting type of 'int'. Got type of 'float'
RuleCheckAnyKw Usage
RuleCheckAnyKw decorator allows each arg of a function match one of the rules specified.
Each arg can have seperate rules applied.
Includes features:
RuleCheckAnyKw constructor args arg_info and rules work together.
arg_info is a dictionary with a key of str that matches an arg name of the function that
is being decorated.
arg_info value is one of the following:
intis an index of an item inrules
IRulea rule to match
Iterator[IRule]a list of rules to match
arg_info can be mixed.
rules is a list of rules to match. Each element is an IRule or a list of IRule.
RuleCheckAnyKw decorated function.
from kwhelp.decorator import RuleCheckAnyKw
import kwhelp.rules as rules
@RuleCheckAnyKw(arg_info={"speed": 0, "limit": 0, "hours": 0, "name": 1},
rules=[(rules.RuleIntPositive, rules.RuleFloatPositive),
rules.RuleStrNotNullEmptyWs])
def speed_msg(speed, limit, **kwargs) -> str:
name = kwargs.get('name', 'You')
if limit > speed:
msg = f"Current speed is '{speed}'. {name} may go faster as the limit is '{limit}'."
elif speed == limit:
msg = f"Current speed is '{speed}'. {name} are at the limit."
else:
msg = f"Please slow down limit is '{limit}' and current speed is '{speed}'."
if 'hours' in kwargs:
msg = msg + f" Current driving hours is '{kwargs['hours']}'."
return msg
>>> result = speed_msg(speed=45, limit=60)
>>> print(result)
Current speed is '45'. You may go faster as the limit is '60'.
>>> result = speed_msg(speed=45, limit=60, name="John")
>>> print(result)
Current speed is '45'. John may go faster as the limit is '60'.
If all rules fail validation then a RuleError is raised.
>>> result = speed_msg(speed=-2, limit=60)
kwhelp.exceptions.RuleError: RuleError: 'speed_msg' error. Argument: 'speed' failed validation.
Rule 'RuleIntPositive' Failed validation.
Expected at least one of the following rules to match: RuleIntPositive, RuleFloatPositive.
RuleCheckAnyKw decorator error.
Inner Error Message: ValueError: Arg error: 'speed' must be a positive int value
>>> result = speed_msg(speed=66, limit=60, name=" ")
kwhelp.exceptions.RuleError: RuleError: 'speed_msg' error. Argument: 'name' failed validation.
Rule 'RuleStrNotNullEmptyWs' Failed validation.
Expected the following rule to match: RuleStrNotNullEmptyWs.
RuleCheckAnyKw decorator error.
Inner Error Message: ValueError: Arg error: 'name' must not be empty or whitespace str
speed_msg decorated with a mixed arg_info with IRule instance and index to rules.
from kwhelp.decorator import RuleCheckAllKw
import kwhelp.rules as rules
@RuleCheckAnyKw(arg_info={"speed": 0, "limit": 0, "hours": 0, "name": rules.RuleStrNotNullEmptyWs},
rules=[(rules.RuleIntPositive, rules.RuleFloatPositive)])
def speed_msg(speed, limit, **kwargs) -> str:
name = kwargs.get('name', 'You')
if limit > speed:
msg = f"Current speed is '{speed}'. {name} may go faster as the limit is '{limit}'."
elif speed == limit:
msg = f"Current speed is '{speed}'. {name} are at the limit."
else:
msg = f"Please slow down limit is '{limit}' and current speed is '{speed}'."
if 'hours' in kwargs:
msg = msg + f" Current driving hours is '{kwargs['hours']}'."
return msg
SubClass Usage
SubClass decorator that requires args of a function to match
or be a subclass of types specificed in constructor.
Includes features:
Sample Classes
from enum import IntEnum, auto
class Color(IntEnum):
RED = auto()
GREEN = auto()
BLUE = auto()
def __str__(self) -> str:
return self._name_
class Base:
def __str__(self) -> str:
return self.__class__.__name__
class Obj:
def __str__(self) -> str:
return self.__class__.__name__
class Foo(Base): pass
class Bar(Foo): pass
class FooBar(Bar): pass
class ObjFoo(Obj): pass
*argsThis example requires that all args positive Foo or positive ObjFoo.
Each subclass type in SubClass constructor represents one positional arg.
In the following example two postional args are expected.
from kwhelp.decorator import SubClass
@SubClass(Foo, ObjFoo)
def do_something(*args):
return [str(arg) for arg in args]
Expected args pass validatation.
>>> print(do_something(Foo(), ObjFoo()))
['Foo', 'ObjFoo']
Types dictate that if first arg is not a subclass of Foo or
first arg is not a subclass of ObjFoo then an error will be raised.
>>> print(do_something(Foo(), Obj()))
TypeError: Arg in 2nd position is expected to be of a subclass of 'ObjFoo'.
SubClass decorator error.
Arguments passed into function must match the same number of SubClass Types.
If not the same count then a ValueError is rasied.
>>> do_something(Foo(), ObjFoo(), Bar())
ValueError: Invalid number of arguments for do_something()
SubClass decorator error.
from kwhelp.decorator import SubClass
@SubClass((FooBar, ObjFoo),(Color, Obj))
def do_something(*args):
return str(first), str(last)
This call to do_something raises no errors.
>>> print(do_something(FooBar(), Color.RED))
['FooBar', 'RED']
This call to do_something raised TypeError due to first arg
not being a subclass of FooBar or ObjFoo.
>>> print(do_something(Foo(), Color.RED))
TypeError: Arg in 1st position is expected to be of a subclass of 'ObjFoo' or 'FooBar'.
SubClass decorator error.
Decorating when a function has key, value pairs for arguments is
the same pattern as *args. SubClass type one matches position one of function.
SubClass type two matches postiion two of function etc…
from kwhelp.decorator import SubClass
@SubClass(Foo, ObjFoo, Color)
def do_something(first, last, color=Color.GREEN):
return str(first), str(last) , str(color)
>>> print(do_something(last=ObjFoo(), first=Foo()))
('Foo', 'ObjFoo', 'GREEN')
>>> print(do_something(last=ObjFoo(), first=1))
TypeError: Arg 'first' is expected be a subclass of 'Foo'.
SubClass decorator error.
In python numbers and str instances are classes. SubClass
can also be used to test for numbers and strings.
@SubClass(int, (int, float), str)
def do_something(first, last, end):
return first, last , end
>>> print(do_something(1, 17, "!!!"))
(1, 17, '!!!')
>>> do_something(1, 44.556, "!!!")
(1, 44.556, '!!!')
>>> print(do_something(1, 44.556))
ValueError: Invalid number of arguments for do_something()
SubClass decorator error.
>>> print(do_something(1, 44.556, 10))
TypeError: Arg 'end' is expected be a subclass of 'str'.
SubClass decorator error.
opt_all_args argument allows the last class type passed into SubClass to
validate all remaining arguments of wrapped function.
For more examples see opt_all_args.
@SubClass(float, (float, int), opt_all_args=True)
def sum_num(*args):
return sum(args)
The first arg of sum_num must be a float. Remaining args can be float or int.
>>> print(sum_num(1.3, 44.556, 10, 22, 45, 7.88))
130.736
>>> print(sum_num(1, 44.556, 10, 22, 45, 7.88))
TypeError: Arg in 1st position is expected to be of a subclass of 'float'.
SubClass decorator error.
>>> print(sum_num(1.3, 44.556, 10, 22, 45, 7.88, "77"))
TypeError: Arg in 7th position is expected to be of a subclass of 'float' or 'int'.
SubClass decorator error.
The arguments are validated by SubClass can be filtered by setting opt_args_filter option.
For more examples see opt_args_filter.
In the following example all *args must of or derived from clase Base.
opt_args_filter=DecArgEnum.ARGS filters SubClass to only process *args.
from kwhelp.decorator import SubClass, DecArgEnum
@SubClass(Base, opt_all_args=True, opt_args_filter=DecArgEnum.ARGS)
def foo(*args, msg: str):
result = [str(t) for t in args]
return msg + ', '.join(result)
>>> result = foo(Foo(), Bar(), FooBar(), ObjFoo(), msg='Summary: ')
>>> print(result)
Summary: Foo, Bar, FooBar, Foo
>>> result = foo(Foo(), Bar(), FooBar(), ObjFoo(), msg='Summary: ')
TypeError: Arg in 4th position is expected to be of a subclass of 'Base'.
SubClass decorator error.
SubClass can be combined with other decorators.
The following example limits how many args are allowed by applying
ArgsMinMax decorator.
from kwhelp.decorator import SubClass, ArgsMinMax
@ArgsMinMax(max=6)
@SubClass(float, (float, int), opt_all_args=True)
def sum_num(*args):
return sum(args)
>>> print(sum_num(1.3, 44.556, 10, 22, 45, 7.88))
130.736
>>> print(sum_num(1, 44.556, 10, 22, 45, 7.88, 100))
ValueError: Invalid number of args pass into 'sum_num'.
Expected max of '6'. Got '7' args.
ArgsMinMax decorator error.
SubClasskKw Usage
SubClasskKw decorator that requires args of a function to match
or be a subclass of types specificed in constructor. Each arg can have seperate rules applied.
Includes features:
SubClasskKw constructor args arg_info and rules work together.
arg_info is a dictionary with a key of str that matches an arg name of the function that
is being decorated.
arg_info value is one of the following:
intis an index of an item inrules
typea type to match
arg_info can be mixed.
types is a list of type to match.
Sample Classes
from enum import IntEnum, auto
class Color(IntEnum):
RED = auto()
GREEN = auto()
BLUE = auto()
def __str__(self) -> str:
return self._name_
class Base:
def __str__(self) -> str:
return self.__class__.__name__
class Obj:
def __str__(self) -> str:
return self.__class__.__name__
class Foo(Base): pass
class Bar(Foo): pass
class FooBar(Bar): pass
class ObjFoo(Obj): pass
SubClasskKw decorated function.
from kwhelp.decorator import SubClasskKw
@SubClasskKw(arg_info={"first": 0, "second": 0, "obj": 0, "color": 1},
types=[(Foo, Obj), Color])
def myfunc(first, second, **kwargs):
color = kwargs.get("color", Color.BLUE)
return (str(first), str(second), str(kwargs['obj']), str(color))
>>> result = myfunc(first=Foo(), second=ObjFoo(), obj=FooBar())
>>> print(result)
('Foo', 'ObjFoo', 'FooBar', 'BLUE')
>>> result = myfunc(first=Foo(), second=ObjFoo(), color=Color.RED, obj=FooBar())
>>> print(result)
('Foo', 'ObjFoo', 'FooBar', 'RED')
If types fail validation then a TypeError is raised.
>>> result = myfunc(first=Foo(), second=ObjFoo(), color=1, obj=FooBar())
TypeError: Arg 'color' is expected to be of a subclass of 'Color'.
SubClasskKw decorator error.
SubClasskKw arg_info contains types and indexes.
Types of arg_info are requied to match function arguments directly.
Indexes are an index of types that match function arguments.
from kwhelp.decorator import SubClasskKw
@SubClasskKw(arg_info={"first": 0, "second": 0, "obj": 0, "color": Color},
types=[(Foo, Obj), Color])
def myfunc(first, second, **kwargs):
color = kwargs.get("color", Color.BLUE)
return (str(first), str(second), str(kwargs['obj']), str(color))
>>> result = myfunc(first=Foo(), second=ObjFoo(), obj=FooBar())
>>> print(result)
('Foo', 'ObjFoo', 'FooBar', 'BLUE')
>>> result = myfunc(first=Foo(), second=ObjFoo(), color=1, obj=FooBar())
TypeError: Arg 'color' is expected to be of a subclass of 'Color'.
SubClasskKw decorator error.
In python numbers and str instances are classes. SubClasskKw
can also be used to test for numbers and strings.
from kwhelp.decorator import SubClasskKw
@SubClasskKw(arg_info={"first": 0, "second": 0, "obj": 0, "last": 1},
types=[(int, float), str])
def myfunc(first, second, **kwargs):
last = kwargs.get("last", "The End!")
return (first, second, kwargs['obj'], last)
>>> result = myfunc(first=22.55, second=555, obj=-12.45, last="!!!")
>>> print(result)
(22.55, 555, -12.45, '!!!')
>>> result = myfunc(first=22.55, second=555, obj=None, last="!!!")
>>> print(result)
TypeError: Arg 'obj' is expected to be of a subclass of 'float' or 'int'.
SubClasskKw decorator error.
TypeCheck Usage
TypeCheck decorator reqires that each args of a function match a type.
Includes features:
*argsThis example requires that all args int or float.
from kwhelp.decorator import TypeCheck
@TypeCheck(int, float)
def add_numbers(*args) -> float:
result = 0.0
for arg in args:
result += float(arg)
return result
Adding numbers works as expected.
>>> result = add_numbers(1, 4, 6.9, 3.9, 7.3)
>>> print(result)
23.1
Types dictate that if a type is not int or float then an error will be raised.
>>> result = add_numbers(2, 1.2, "4")
TypeError: Arg Value is expected to be of 'float' or 'int' but got 'str'.
TypeCheck decorator error.
This example requires that all args are int or float.
from kwhelp.decorator import TypeCheck
@TypeCheck(int, float)
def speed_msg(speed, limit, **kwargs) -> str:
if limit > speed:
msg = f"Current speed is '{speed}'. You may go faster as the limit is '{limit}'."
elif speed == limit:
msg = f"Current speed is '{speed}'. You are at the limit."
else:
msg = f"Please slow down limit is '{limit}' and you are currenlty going '{speed}'."
if 'hours' in kwargs:
msg = msg + f" Current driving hours is '{kwargs['hours']}'"
return msg
Adding positive numbers works as expected.
>>> result = speed_msg(speed=45, limit=60)
>>> print(result)
Current speed is '45'. You may go faster as the limit is '60'.
>>> result = speed_msg(speed=66, limit=60, hours=4.7)
>>> print(result)
Please slow down limit is '60' and you are currenlty going '66'. Current driving hours is '4.7
Types dictate that if a type is not int or float then an error will be raised.
>>> result = speed_msg(speed=45, limit="Fast")
TypeError: Arg 'limit' is expected to be of 'float' or 'int' but got 'str'.
TypeCheck decorator error.
The arguments are validated by TypeCheck can be filtered by setting opt_args_filter option.
For more examples see opt_args_filter.
In the following example all *args must of of type float or int.
opt_args_filter=DecArgEnum.ARGS filters TypeCheck to only process *args.
from kwhelp.decorator import TypeCheck, DecArgEnum
@TypeCheck(float, int, opt_args_filter=DecArgEnum.ARGS)
def sum_num(*args, msg: str):
_sum = sum(args)
return msg + str(_sum)
>>> result = sum_num(102, 2.45, 34.55, -24, 5.8, -6, msg='Total: ')
>>> Total: 114.8
Total: 21
>>> sum_num(102, "two", 34.55, -24, 5.8, -6, msg='Total: ')
TypeError: Arg Value is expected to be of 'float' or 'int' but got 'str'.
TypeCheck decorator error.
By combining TypeCheck decorators with different opt_args_filter settings
it is possible to required diferent types for *args, **kwargs and Named Args.
from kwhelp.decorator import TypeCheck, DecArgEnum
@TypeCheck(str, opt_args_filter=DecArgEnum.NAMED_ARGS)
@TypeCheck(float, int, opt_args_filter=DecArgEnum.ARGS)
def sum_num(*args, msg: str):
_sum = sum(args)
return msg + str(_sum)
>>> result = sum_num(102, 2.45, 34.55, -24, 5.8, -6, msg='Total: ')
>>> Total: 114.8
Total: 21
>>> sum_num(102, "two", 34.55, -24, 5.8, -6, msg='Total: ')
TypeError: Arg Value is expected to be of 'float' or 'int' but got 'str'.
TypeCheck decorator error.
>>> sum_num(102, 2.45, 34.55, -24, 5.8, -6, msg=22)
TypeError: Arg 'msg' is expected to be of 'str' but got 'int'.
TypeCheck decorator error.
TypeCheckKw Usage
TypeCheckKw decorator allows each arg of a function match one of the types specified.
Each arg can have seperate rules applied.
Includes features:
TypeCheckKw constructor args arg_info and rules work together.
arg_info is a dictionary with a key of str that matches an arg name of the function that
is being decorated.
arg_info value is one of the following:
intis an index of an item inrules
typea type to match
arg_info can be mixed.
types is a list of type to match.
TypeCheckKw decorated function.
from kwhelp.decorator import TypeCheckKw
@TypeCheckKw(arg_info={"speed": 0, "limit": 0, "hours": 0, "name": 1},
types=[(int, float), str])
def speed_msg(speed, limit, **kwargs) -> str:
name = kwargs.get('name', 'You')
if limit > speed:
msg = f"Current speed is '{speed}'. {name} may go faster as the limit is '{limit}'."
elif speed == limit:
msg = f"Current speed is '{speed}'. {name} are at the limit."
else:
msg = f"Please slow down limit is '{limit}' and current speed is '{speed}'."
if 'hours' in kwargs:
msg = msg + f" Current driving hours is '{kwargs['hours']}'."
return msg
>>> result = speed_msg(speed=45, limit=60)
>>> print(result)
Current speed is '45'. You may go faster as the limit is '60'.
>>> result = speed_msg(speed=45, limit=60, name="John")
>>> print(result)
Current speed is '45'. John may go faster as the limit is '60'.
If types fail validation then a TypeError is raised.
>>> result = speed_msg(speed=-2, limit=60, name=17, hours=5)
TypeError: Arg 'name' is expected to be of 'str' but got 'int'.
TypeCheckKw decorator error.
TypeCheckKw arg_info contains types and indexes.
Types of arg_info are requied to match function arguments directly.
Indexes are an index of types that match function arguments.
from kwhelp.decorator import TypeCheckKw
@TypeCheckKw(arg_info={"speed": 0, "limit": 0, "hours": 0, "name": str},
types=[(int, float)])
def speed_msg(speed, limit, **kwargs) -> str:
name = kwargs.get('name', 'You')
if limit > speed:
msg = f"Current speed is '{speed}'. {name} may go faster as the limit is '{limit}'."
elif speed == limit:
msg = f"Current speed is '{speed}'. {name} are at the limit."
else:
msg = f"Please slow down limit is '{limit}' and current speed is '{speed}'."
if 'hours' in kwargs:
msg = msg + f" Current driving hours is '{kwargs['hours']}'."
return msg
Callcounter Usage
callcounter Decorator method that adds call_count attribute to decorated method.
call_count is 0 if method has not been called.call_count increases by 1 each time method is been called.from kwhelp.decorator import calltracker
@callcounter
def foo(msg):
print(msg)
>>> print("Call Count:", foo.call_count)
0
>>> foo("Hello")
Hello
>>> print("Call Count:", foo.call_count)
1
>>> foo("World")
World
>>> print("Call Count:", foo.call_count)
2
Note
This decorator needs to be the topmost decorator applied to a method
Calltracker Usage
calltracker decorator method that adds has_been_called attribute to decorated method.
has_been_called is False if method has not been called.has_been_called is True if method has been called.from kwhelp.decorator import calltracker
@calltracker
def foo(msg):
print(msg)
>>> print(foo.has_been_called)
False
>>> foo("Hello World")
Hello World
>>> print(foo.has_been_called)
True
Note
This decorator needs to be the topmost decorator applied to a method
Singleton Usage
singleton decorator that makes a class a singleton class
Example class that becomes a singleton class onece attribute is applied.
from kwhelp.decorator import singleton, RuleCheckAll
from kwhelp import rules
@singleton
class Logger:
@RuleCheckAll(rules.RuleStrNotNullEmptyWs, ftype=DecFuncEnum.METHOD)
def log(self, msg):
print(msg)
All created instances are the same instance.
>>> logger1 = Logger()
>>> logger2 = Logger()
>>> print(logger1 is logger1)
True
See also
Example
The following example ensures all function args are a positive int or a positive float.
from kwhelp.decorator import RuleCheckAny
import kwhelp.rules as rules
@RuleCheckAny(rules.RuleIntPositive, rules.RuleFloatPositive)
def speed_msg(speed, limit, **kwargs) -> str:
if limit > speed:
msg = f"Current speed is '{speed}'. You may go faster as the limit is '{limit}'."
elif speed == limit:
msg = f"Current speed is '{speed}'. You are at the limit."
else:
msg = f"Please slow down limit is '{limit}' and you are currenlty going '{speed}'."
if 'hours' in kwargs:
msg = msg + f" Current driving hours is '{kwargs['hours']}'"
return msg
Decorators
Decorators can be used to validate functions.
See also
Example
The following example ensures all function args are a positive int or a positive float.
from kwhelp.decorator import RuleCheckAny
import kwhelp.rules as rules
@RuleCheckAny(rules.RuleIntPositive, rules.RuleFloatPositive)
def speed_msg(speed, limit, **kwargs) -> str:
if limit > speed:
msg = f"Current speed is '{speed}'. You may go faster as the limit is '{limit}'."
elif speed == limit:
msg = f"Current speed is '{speed}'. You are at the limit."
else:
msg = f"Please slow down limit is '{limit}' and you are currenlty going '{speed}'."
if 'hours' in kwargs:
msg = msg + f" Current driving hours is '{kwargs['hours']}'"
return msg
Features
ftype
ftype option is DecFuncEnum argument.
ftype sets the type of function, method, property etc.
Function
Default for ftype is function. Therefore it is not necessary to set ftype on functions.
@RuleCheckAll(rules.RuleIntPositive)
def fib(n: int):
def _fib(_n, memo={}):
if _n in memo: return memo[_n]
if _n <= 2: return 1
memo[_n] = _fib(_n - 1, memo) + _fib(_n - 2, memo)
return memo[_n]
return _fib(n)
Run function.
>>> print(fib(7))
8
>>> print(fib(8))
13
>>> print(fib(6))
21
>>> print(fib(50))
2586269025
>>> print(fib(-50))
kwhelp.exceptions.RuleError: RuleError: 'fib' error.
Rule 'RuleIntPositive' Failed validation.
Expected the following rule to match: RuleIntPositive.
Inner Error Message: ValueError: Arg error: 'arg' must be a positive int value
>>> print(fib("3"))
kwhelp.exceptions.RuleError: RuleError: 'fib' error.
Rule 'RuleIntPositive' Failed validation.
Expected the following rule to match: RuleIntPositive.
Inner Error Message: TypeError: Argument Error: 'arg' is expecting type of 'int'. Got type of 'str'
Class
For class method ftype is set to DecFuncEnum.METHOD
class Calc:
@RuleCheckAll(rules.RuleIntPositive, ftype=DecFuncEnum.METHOD)
def fib(self, n: int):
def _fib(_n, memo={}):
if _n in memo: return memo[_n]
if _n <= 2: return 1
memo[_n] = _fib(_n - 1, memo) + _fib(_n - 2, memo)
return memo[_n]
return _fib(n)
>>> c = Calc()
>>> print(c.fib(7))
8
>>> print(c.fib(8))
13
>>> print(c.fib(6))
21
>>> print(c.fib(50))
2586269025
>>> print(c.fib(-50))
kwhelp.exceptions.RuleError: RuleError: 'fib' error.
Rule 'RuleIntPositive' Failed validation.
Expected the following rule to match: RuleIntPositive.
Inner Error Message: ValueError: Arg error: 'arg' must be a positive int value
Class Property
For class property ftype is set to DecFuncEnum.PROPERTY_CLASS
class Foo:
@RuleCheckAny(RuleIntPositive, RuleFloatPositive, ftype=DecFuncEnum.METHOD)
def __init__(self, test_value) -> None:
self._test = test_value
@property
def test(self):
return self._test
@test.setter
@RuleCheckAny(RuleIntPositive, RuleFloatPositive, ftype=DecFuncEnum.PROPERTY_CLASS)
def test(self, value):
self._test = value
>>> f = Foo(test_value=22)
>>> print(f.test)
22
>>> f.test = 127.899
>>> print(f.test)
127.899
>>> f.test = -33
kwhelp.exceptions.RuleError: RuleError: 'test' error.
Rule 'RuleIntPositive' Failed validation.
Expected at least one of the following rules to match: RuleIntPositive, RuleFloatPositive.
Inner Error Message: ValueError: Arg error: 'arg' must be a positive int value
Class staticmethod
For staticmethod method ftype is set to DecFuncEnum.METHOD_STATIC
class Calc:
@staticmethod
@RuleCheckAll(rules.RuleIntPositive, ftype=DecFuncEnum.METHOD_STATIC)
def fib(n: int):
def _fib(_n, memo={}):
if _n in memo: return memo[_n]
if _n <= 2: return 1
memo[_n] = _fib(_n - 1, memo) + _fib(_n - 2, memo)
return memo[_n]
return _fib(n)
>>> print(Calc.fib(7))
8
>>> print(Calc.fib(8))
13
>>> print(Calc.fib(6))
21
>>> print(Calc.fib(50))
2586269025
Class classmethod
For classmethod ftype is set to DecFuncEnum.METHOD_CLASS
class Calc:
@classmethod
@RuleCheckAll(rules.RuleIntPositive, ftype=DecFuncEnum.METHOD_CLASS)
def fib(cls, n: int):
def _fib(_n, memo={}):
if _n in memo: return memo[_n]
if _n <= 2: return 1
memo[_n] = _fib(_n - 1, memo) + _fib(_n - 2, memo)
return memo[_n]
return _fib(n)
>>> print(Calc.fib(7))
8
>>> print(Calc.fib(8))
13
>>> print(Calc.fib(6))
21
>>> print(Calc.fib(50))
2586269025
opt_all_args
opt_all_args argument allows the last paramater passed into *args to
validate all remaining arguments of wrapped function.
from kwhelp.decorator import AcceptedTypes
@AcceptedTypes(float, (float, int), opt_all_args=True)
def sum_num(*args):
return sum(args)
The first arg of sum_num must be a float. Remaining args can be float or int.
>>> print(sum_num(1.3, 44.556, 10, 22, 45, 7.88))
130.736
>>> print(sum_num(1, 44.556, 10, 22, 45, 7.88))
TypeError: Arg in 1st position of is expected to be of '<class 'float'>' but got 'int'
AcceptedTypes decorator error.
>>> print(sum_num(1.3, 44.556, 10, 22, 45, 7.88, "77"))
TypeError: Arg in 3rd position of is expected to be of '(<class 'float'>, <class 'int'>)' but got 'str'
AcceptedTypes decorator error.
opt_args_filter
opt_args_filter allows decorators that support it filter which type of argument will be validated.
The following example is with AcceptedTypes but is similar for all decorators that
support opt_args_filter option.
ARGS
DecArgEnum.ARGS filter. Only *args are validated.
from kwhelp.decorator import AcceptedTypes, DecArgEnum
@AcceptedTypes(int, opt_all_args=True, opt_args_filter=DecArgEnum.ARGS)
def foo(*args, first, last, **kwargs):
return [*args] + [first, last] + [v for _, v in kwargs.items()]
>>> result = foo(1, 2, 3, 4, 5, 6, first="one", one="1st", two="2nd", third="3rd")
>>> print(result)
[1, 2, 3, 4, 5, 6, 'one', '!!!', '1st', '2nd', '3rd']
>>> foo(1, 45.66, 3, 4, 5, 6, first="one", one="1st", two="2nd", third="3rd")
TypeError: Arg in 2nd position of is expected to be of 'int' but got 'float'.
AcceptedTypes decorator error.
NAMED_ARGS
DecArgEnum.NAMED_ARGS filter. Only named args are validated. *args and **kwargs are excluded.
from kwhelp.decorator import AcceptedTypes, DecArgEnum
@AcceptedTypes(int, int, opt_args_filter=DecArgEnum.NAMED_ARGS)
def foo(*args, first, last, **kwargs):
return [*args] + [first, last] + [v for _, v in kwargs.items()]
>>> result = foo("a", "b", "c", first=1, last= 3, one="1st", two="2nd", third="3rd")
>>> print(result)
['a', 'b', 'c', 1, 3, '1st', '2nd', '3rd']
>>> result = foo("a", "b", "c", first=1.5, last=3, one="1st", two="2nd", third="3rd")
TypeError: Arg 'first' in 1st position is expected to be of 'int' but got 'float'.
AcceptedTypes decorator error.
KWARGS
DecArgEnum.KWARGS filter. Only **kwargs are validated. *args and named args are excluded.
from kwhelp.decorator import AcceptedTypes, DecArgEnum
@AcceptedTypes((int, float), opt_all_args=True, opt_args_filter=DecArgEnum.KWARGS)
def foo(*args, first, last="!", **kwargs):
return [*args] + [first, last] + [v for _, v in kwargs.items()]
>>> result = foo("a", "b", "c", first=-100, one=101, two=2.2, third=33.33)
>>> print(result)
['a', 'b', 'c', -100, '!', 101, 2.2, 33.33]
>>> result = foo("a", "b", "c", first=-100, one=101, two="two", third=33.33)
TypeError: Arg 'two' in 2nd position is expected to be of 'float' or 'int' but got 'str'.
AcceptedTypes decorator error.
NO_ARGS
DecArgEnum.NO_ARGS filter. Only all args except for *args.
from kwhelp.decorator import AcceptedTypes, DecArgEnum
@AcceptedTypes((int, float), opt_all_args=True, opt_args_filter=DecArgEnum.NO_ARGS)
def foo(*args, first, last=1001, **kwargs):
return [*args] + [first, last] + [v for _, v in kwargs.items()]
>>> result = foo("a", "b", "c", first=-100, one=101, two=22.22, third=33.33)
>>> print(result)
['a', 'b', 'c', -100, 1001, 101, 22.22, 33.33]
>>> result = foo("a", "b", "c", first=-100, one="1st", two=22.22, third=33.33)
TypeError: Arg 'one' in 3rd position is expected to be of 'float' or 'int' but got 'str'.
AcceptedTypes decorator error
>>> result = foo("a", "b", "c", first=-100, one=101.11, two="2nd", third=33.33)
TypeError: Arg 'two' in 4th position is expected to be of 'float' or 'int' but got 'str'.
AcceptedTypes decorator error.
opt_logger
opt_logger option requires a logger. When a logger is passed in then the decorator will
log to the logger when validation fails.
Note
When opt_return option is set and/or raise_error is False then logging
will not take place as no validation error are raised.
Example logger and function with a decorator that uses logger.
import logging
from pathlib import Path
from kwhelp.decorator import RuleCheckAll
from kwhelp.rules import RuleIntPositive
def _create_logger(level:int, log_path: Path) -> logging.Logger:
"""
Creates a logging object and returns it
"""
logger = logging.getLogger("default_logger")
logger.setLevel(level)
# create the logging file handler
fh = logging.FileHandler(str(log_path))
fmt = '%(asctime)s - %(name)s - %(levelname)s - %(message)s'
formatter = logging.Formatter(fmt)
fh.setFormatter(formatter)
# add handler to logger object
logger.addHandler(fh)
return logger
default_logger = _create_logger(level=logging.DEBUG ,log_path=(Path.home() / 'mylog.log'))
@RuleCheckAll(RuleIntPositive, opt_logger=default_logger)
def add_positives(*args) -> int:
return sum(args)
Call sample function.
>>> try:
>>> result = add_positives(1, 33, -3)
>>> print(result)
>>> except Exception as e:
>>> print(e)
RuleError: 'add_positives' error.
Rule 'RuleIntPositive' Failed validation.
Expected the following rule to match: RuleIntPositive.
RuleCheckAll decorator error.
Inner Error Message: ValueError: Arg error: 'arg' must be a positive int value
2021-11-18 07:58:17,995 - default_logger - ERROR - RuleError: 'add_positives' error.
Rule 'RuleIntPositive' Failed validation.
Expected the following rule to match: RuleIntPositive.
RuleCheckAll decorator error.
Inner Error Message: ValueError: Arg error: 'arg' must be a positive int value
Traceback (most recent call last):
File "/home/paul/Documents/Projects/Python/Publish/kwargs/kwhelp/checks/__init__.py", line 237, in _validate_rules_all
result = result & rule_instance.validate()
File "/home/paul/Documents/Projects/Python/Publish/kwargs/kwhelp/rules/__init__.py", line 347, in validate
raise ValueError(
ValueError: Arg error: 'arg' must be a positive int value
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "/home/paul/Documents/Projects/Python/Publish/kwargs/kwhelp/decorator/__init__.py", line 1648, in wrapper
is_valid = self._rulechecker.validate_all(**arg_name_values)
File "/home/paul/Documents/Projects/Python/Publish/kwargs/kwhelp/checks/__init__.py", line 311, in validate_all
result = result & self._validate_rules_all(key=k, field=k, value=v)
File "/home/paul/Documents/Projects/Python/Publish/kwargs/kwhelp/checks/__init__.py", line 240, in _validate_rules_all
raise RuleError(
kwhelp.exceptions.RuleError: RuleError:
Rule 'RuleIntPositive' Failed validation.
Expected the following rule to match: RuleIntPositive.
Inner Error Message: ValueError: Arg error: 'arg' must be a positive int value
opt_return
Many decorators supports optoinal opt_return option.
opt_return sets what will be be returned if validation fails.
Noramlly decorators will raise an error if validation fails.
In the following example by setting opt_return to False
then when validation fails False will be returned instead of an error
being raised.
from kwhelp.decorator import ArgsLen, RuleCheckAll
from kwhelp import rules
@ArgsLen(2, opt_return=False)
@RuleCheckAll(rules.RuleStrNotNullEmptyWs, opt_return=False)
def is_ab(*args):
if args[0].lower() == "a" and args[1].lower() == "b":
return True
return False
>>> print(is_ab())
False
>>> print(is_ab(1))
False
>>> print(is_ab(1, 2))
False
>>> print(is_ab('ab'))
False
>>> print(is_ab('a', 'b', 'c'))
False
>>> print(is_ab('a', 'b'))
True
>>> print(is_ab('A', 'B'))
True
>>> print(is_ab(["a", "b"]))
False
>>> print(is_ab(*["a", "b"]))
True
raise_error
Some decorators supports optoinal raise_error bool option.
raise_error sets if a an error will be validation fails.
If raise_error is set to False then a attribute will be
added to the decorated funciton.
from kwhelp.decorator import RuleCheckAll
from kwhelp import rules
@RuleCheckAll(rules.RuleIntPositive, raise_error=False)
def add_positives(*args) -> float:
result = 0
for arg in args:
result += arg
return result
>>> print(add_positives.is_rules_all_valid)
True
>>> result = add_positives(2, -4)
>>> print(add_positives.is_rules_all_valid)
False
>>> result = add_positives(2, 4)
>>> print(add_positives.is_rules_all_valid)
True
>>> print(result)
6
type_instance_check
Many type validation decorators supports optoinal type_instance_check bool option.
True
When type_instance_check is True then if type does not match then an instance check will also be done.
from pathlib import Path
from kwhelp.decorator import AcceptedTypes
@AcceptedTypes(Path, type_instance_check=True)
def is_file_exist(arg):
return True
>>> p = Path("home", "user")
>>> print(is_file_exist(arg=p))
True
False
from pathlib import Path
from kwhelp.decorator import AcceptedTypes
@AcceptedTypes(Path, type_instance_check=False)
def is_file_exist(arg):
return True
>>> p = Path("home", "user")
>>> print(is_file_exist(arg=p))
TypeError: Arg 'arg' in 1st position is expected to be of '<class 'pathlib.Path'>' but got 'PosixPath'
Explanation
In some cases such as Mulitple Inheritance type check may not pass
In the following example type check for str is True however, Path is false.
>>> from pathlib import Path
>>> s = ""
>>> print(type(s) is str)
True
>>> p = Path("home", "user")
>>> print(type(p) is Path)
False
In the following example instance check for Path is True
>>> from pathlib import Path
>>> p = Path("home", "user")
>>> print(isinstance(p, Path))
False
Decorator Index
Rules
Rules allow validation of kwargs values.
IRule
New rules can be created by inheriting from IRule interface/class
Example Rule:
from kwhelp.rules import IRule
class RuleIntRangeZeroNine(IRule):
'''
Rule to ensure a integer from 0 to 9.
'''
def validate(self) -> bool:
if not isinstance(self.field_value, int):
return False
if self.field_value < 0 or self.field_value > 9:
if self.raise_errors:
raise ValueError(
f"Arg error: '{self.key}' must be a num from 0 to 9")
return False
return True
Included Rules
Examples
Using Callbacks
Using callback:
Example:
from kwhelp import KwargsHelper, AfterAssignEventArgs, BeforeAssignEventArgs, AssignBuilder
class MyClass:
def __init__(self, **kwargs):
self._loop_count = -1
kw = KwargsHelper(originator=self, obj_kwargs={**kwargs})
ab = AssignBuilder()
kw.add_handler_before_assign(self._arg_before_cb)
kw.add_handler_after_assign(self._arg_after_cb)
ab.append(key='exporter', require=True, types=[str])
ab.append(key='name', require=True, types=[str],
default='unknown')
ab.append(key='file_name', require=True, types=[str])
ab.append(key='loop_count', types=[int],
default=self._loop_count)
result = True
# by default assign will raise errors if conditions are not met.
for arg in ab:
result = kw.assign_helper(arg)
if result == False:
break
if result == False:
raise ValueError("Error parsing kwargs")
def _arg_before_cb(self, helper: KwargsHelper,
args: BeforeAssignEventArgs) -> None:
# callback function before value assigned to attribute
if args.key == 'loop_count' and args.field_value < 0:
# cancel will raise CancelEventError unless
# KwargsHelper constructor has cancel_error=False
args.cancel = True
if args.key == 'name' and args.field_value == 'unknown':
args.field_value = 'None'
def _arg_after_cb(self, helper: KwargsHelper,
args: AfterAssignEventArgs) -> None:
# callback function after value assigned to attribute
if args.key == 'name' and args.field_value == 'unknown':
raise ValueError(
f"{args.key} This should never happen. value was suppose to be reassigned")
@property
def exporter(self) -> str:
return self._exporter
@property
def file_name(self) -> str:
return self._file_name
@property
def name(self) -> str:
return self._name
@property
def loop_count(self) -> int:
return self._loop_count
>>> my_class = MyClass(exporter='json', file_name='data.json', loop_count=3)
>>> print(my_class.exporter)
json
>>> print(my_class.file_name)
data.json
>>> print(my_class.name)
None
>>> print(my_class.loop_count)
3
Using Callbacks & Rules
Using rules with Callback:
Example:
from kwhelp import KwargsHelper, AfterAssignEventArgs, BeforeAssignEventArgs, AssignBuilder
import kwhelp.rules as rules
class MyClass:
def __init__(self, **kwargs):
self._loop_count = -1
kw = KwargsHelper(self, {**kwargs})
ab = AssignBuilder()
kw.add_handler_before_assign(self._arg_before_cb)
kw.add_handler_after_assign(self._arg_after_cb)
ab.append(key='exporter', rules=[rules.RuleStr])
ab.append(key='name', require=True, rules=[rules.RuleStr],
default='unknown')
ab.append(key='file_name', require=True, rules_all=[
rules.RuleStr, rules.RuleStrNotNullOrEmpty])
ab.append(key='loop_count', require=True, rules_all=[
rules.RuleInt, rules.RuleIntPositive],
default=self._loop_count)
result = True
# by default assign will raise errors if conditions are not met.
for arg in ab:
result = kw.assign_helper(arg)
if result == False:
break
if result == False:
raise ValueError("Error parsing kwargs")
def _arg_before_cb(self, helper: KwargsHelper,
args: BeforeAssignEventArgs) -> None:
if args.key == 'name' and args.field_value == 'unknown':
args.field_value = 'None'
def _arg_after_cb(self, helper: KwargsHelper,
args: AfterAssignEventArgs) -> None:
# callback function after value assigned to attribute
if args.key == 'name' and args.field_value == 'unknown':
raise ValueError(
f"{args.key} This should never happen. value was suppose to be reassigned")
@property
def exporter(self) -> str:
return self._exporter
@property
def file_name(self) -> str:
return self._file_name
@property
def name(self) -> str:
return self._name
@property
def loop_count(self) -> int:
return self._loop_count
>>> my_class = MyClass(exporter='json', file_name='data.json', loop_count=3)
>>> print(my_class.exporter)
json
>>> print(my_class.file_name)
data.json
>>> print(my_class.name)
None
>>> print(my_class.loop_count)
3
Simple usage
Example:
from kwhelp import KwargsHelper
import kwhelp.rules as rules
class MyClass:
def __init__(self, **kwargs):
self._loop_count = -1
kw = KwargsHelper(self, {**kwargs}, field_prefix='')
kw.assign(key='exporter', types=[str], default='None')
kw.assign(key='name', types=[str], default='unknown')
kw.assign(key='file_name', rules_all=[rules.RuleStrNotNullOrEmpty])
kw.assign(key='loop_count', rules_all=[rules.RuleIntPositive],
default=self._loop_count)
>>> my_class = MyClass(file_name='data.html', name='Best Doc', loop_count=1)
>>> print(my_class.exporter)
None
>>> print(my_class.file_name)
data.html
>>> print(my_class.name)
Best Doc
>>> print(my_class.loop_count)
1
>>> my_class = MyClass(exporter='json', file_name='data.json', loop_count=3)
>>> print(my_class.exporter)
json
>>> print(my_class.file_name)
data.json
>>> print(my_class.name)
None
>>> print(my_class.loop_count)
3
Validation Failure
Raises an error because loop_count is default is -1 and
RuleIntPositive is added to rules.
>>> try:
>>> my_class = MyClass(exporter='html', file_name='data.html', name='Best Doc')
>>> except Exception as e:
>>> print(e)
RuleError: Argument: 'loop_count' failed validation. Rule 'RuleIntPositive' Failed validation.
Expected the following rule to match: RuleIntPositive.
Inner Error Message: ValueError: Arg error: 'loop_count' must be a positive int value
See also
Release Notes
Version 2.7.1
Update opt_logger accept Logger or a LoggerAdapter.
See opt_logger.
Version 2.7.0
Added option opt_logger to many decorators.
See opt_logger.
Versoin 2.6.0
Added Rules:
RulePath
RulePathExist
RulePathNotExist
RuleStrPathExist
RuleStrPathNotExist
Version 2.5.0
Added option opt_args_filter to AcceptedTypes, RuleCheckAll, RuleCheckAny, SubClass, TypeCheck
See opt_args_filter.
Upgraded underling engine to use OrderedDict to ensure order of keys for python <= 3.6
Version 2.4.0
Added SubClass, SubClassKw decorators.
Added opt_all_args feature to AcceptedTypes decorator. See opt_all_args
Update AcceptedTypes decorator. Now passing enum types into constructor no longer require enum type to be passed in as iterable object.
Updated many decorator error message. Now they are a little more human readable.
Version 2.3.0
Added decorator ArgsMinMax
Added Rules:
RuleIterable
RuleNotIterable
Added opt_return feature to many decorators. See opt_return
Version 2.2.1
ArgsLen decorator now allows zero length args.
@ArgsLen(0, 2)
def foo(*args, **kwargs): pass
Version 2.2.0
Added Decorator ArgsLen.
Added Rules:
RuleByteSigned
RuleByteUnsigned
Version 2.1.4
Bug fix for AcceptedTypes Decorator when function has leading named args before positional args.
The following will now work.
@AcceptedTypes(float, str, int, [Color], int, bool)
def myfunc(arg1, arg2, *args, opt=True): pass
Version 2.1.3
- Update fix for python DeprecationWarning:
Using or importing the ABCs from ‘collections’ instead of from ‘collections.abc’ is deprecated
Added Install documentation.
Added Development documentation.
Version 2.1.2
Fix for Decorator AcceptedTypes not working correctly with optional arguments.
Version 2.1.1
Fix for version 2.1.0 setup not building correctly.
Version 2.1.0
New Features
Added Decorators that provided a large range of options for validating function, class input and return values. Also added decorators that provide other functionality such as singleton pattern.
Install
PIP
kwargshelper from PyPI:kwargshelper with:pip install kwargshelper
Also when using pip, it’s good practice to use a virtual environment - see Reproducible Installs below for why, and this guide for details on using virtual environments.
REPRODUCIBLE INSTALLS
As libraries get updated, results from running your code can change, or your code can break completely. It’s important to be able to reconstruct the set of packages and versions you’re using. Best practice is to:
use a different environment per project you’re working on,
record package names and versions using your package installer; each has its own metadata format for this:
Pip: virtual environments and requirements.txt
Project Development
Environment
kwargshelper use a conda environment.
Creating environment
# from root dir of project
$ conda env create --prefix env --file environment.yml
kwhelp
AfterAssignAutoEventArgs Class
- class kwhelp.AfterAssignAutoEventArgs(key: str, originator: object)[source]
After Assign Auto Event Args
See also
- __init__(key: str, originator: object)[source]
Constructor
- Parameters
key (str) – key arg
originator (object) – object that originated event
- property canceled: bool
Get if assigment was canceled by before events
- property field_name: str
The field that will be assigned representing
key.- Getter
Gets the field that will be assigned representing
key.- Setter
Sets the field that will be assigned representing
key.
- property key: str
Gets the key of the key value pair
- property originator: object
Gets object that attributes assigned/modified for
- property success: bool
Get assigning of attribue/value succeeded
AfterAssignEventArgs Class
- class kwhelp.AfterAssignEventArgs(help_args: kwhelp.HelperArgs, originator: object)[source]
After Assign Event Args
See also
- __init__(help_args: kwhelp.HelperArgs, originator: object) None[source]
Constructor
- Parameters
help_args (HelperArgs) – HelperArgs object
originator (object) – Origanating object
- property canceled: bool
Get if assigment was canceled by before events
- property field_name: str
The name of the field that value was assigned
- property field_value: object
The value that is assigned to field_name
- property helper_args: kwhelp.HelperArgs
‘Get the args used to for modify/creating attribute
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes assigned/modified for
- property rules_passed: bool
Get if all applied rules passed
- property success: bool
Determinins if assigning of attribue/value succeeded
- Getter
Get assigning of attribue/value succeeded
- Setter
Sets assigning of attribue/value succeeded
AssignBuilder Class
- class kwhelp.AssignBuilder[source]
Helper class for building list to use with “KwargsHelper.Assing() method
- append(key: str, field: Optional[str] = None, require: bool = False, default: Optional[object] = None, types: Optional[List[type]] = None, rules_all: Optional[List[Callable[[kwhelp.rules.IRule], bool]]] = None, rules_any: Optional[List[Callable[[kwhelp.rules.IRule], bool]]] = None)[source]
Appends dictionary item of parameters to list
- Parameters
key (str) – the key of the key, value pair.
field (Optional[str], optional) – the name of the field.. Defaults to
None.require (bool, optional) – Determins if
keyis required. Defaults toFalse.default (Optional[object], optional) – default value to assign if key value is missing. Defaults to
None.types (Optional[List[type]], optional) – list of one or more types that the value of the key value pair must match. Defaults to
None.rules (Optional[List[Callable[[IRule], bool]]], optional) – Rules to apply. Defaults to
None.
- Raises
TypeError – if
keyis not instance of``str``.ValueError – if
keyis empty or whitespace str.ValueError – if
keyhas already exist.
- append_helper(helper: kwhelp.HelperArgs)[source]
Appends dictionary item of parameters to list
- Parameters
helper (HelperArgs) – parameters to append
- Raises
TypeError – if
helperis not instance ofHelperArgsValueError – if
helper.keyis empty string.ValueError – if
helper.keyalready exist.
- extend(other: kwhelp.AssignBuilder) None[source]
Extents this instance by merging values from other instance of
AssignBuilder.- Parameters
other (AssignBuilder) – instance to merge
- Raises
NotImplementedError – if
otheris not instance ofAssignBuilder.
- remove(item: kwhelp.HelperArgs) None[source]
Removes an instance of
HelperArgsfrom this instance- Parameters
item (HelperArgs) – Object to remove
- Raises
TypeError – if
itemis not instance ofHelperArgs- Returns
None- Return type
[obj]
BeforeAssignAutoEventArgs Class
- class kwhelp.BeforeAssignAutoEventArgs(key: str, value: object, field: str, originator: object)[source]
Before Assign Auto Event Args
See also
- __init__(key: str, value: object, field: str, originator: object)[source]
Constructor
- Parameters
key (str) – Key arg
value (object) – Value to be assigned
field (str) – Field that
valueis to be assigned to.originator (object) – Object that
valueis to be assigned to.all_rules (bool) – Determines if all rules or any rules are to be matched
- property cancel: bool
Cancel arg. If
Trueprocess will be canceled.- Getter
Gets cancel arg
- Setter
Sets cancel arg
- property field_name: str
The field that will be assigned representing
key- Getter
Gets the field that will be assigned representing
key- Setter
Setts the field that will be assigned representing
key
- property field_value: object
The value to be blindly assigned to property
- Getter
Gets the value to be blindly assigned to property
- Setter
Sets the value to be blindly assigned to property
- property key: str
Gets the key of the key value pair
- property originator: object
Gets object that attributes assigned/modified for
BeforeAssignEventArgs Class
- class kwhelp.BeforeAssignEventArgs(help_args: kwhelp.HelperArgs, originator: object)[source]
Before assign event args
See also
- __init__(help_args: kwhelp.HelperArgs, originator: object)[source]
Constructor
- Parameters
help_args (HelperArgs) – HelperArgs object
originator (object) – Origanating object
- property cancel: bool
Cancel arg. If
Trueprocess will be canceled.- Getter
Gets cancel arg
- Setter
Sets cancel arg
- property field_name: str
The name of the field that value will be assigned
- Getter
Gets the name of the field that value will be assigned.
- Setter
Sets the name of the field that value will be assigned.
- property field_value: object
The value that will be assigned
field_name.- Getter
Gets the value that will be assigned
field_name.- Setter
Sets the value that will be assigned
field_name.
- property helper_args: kwhelp.HelperArgs
‘Get the args used to for modify/creating attribute
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes assigned/modified for
HelperArgs Class
- class kwhelp.HelperArgs(key: str, **kwargs)[source]
Helper class that provides KwArgs arguments
- __init__(key: str, **kwargs)[source]
Constructor
- Parameters
key (str) – Key Arg
- Keyword Arguments
default (obj, optional) – Default arg. Default
NO_THINGfield (str, optional) – field arg. Default
Nonerequire (bool, optional) – require arg. Default
Falserules_all (Iterable, optional) – rules_any list. Default Empty List.
rules_any (Iterable, optional) – rules_all list. Default Empty List.
types (set, optional) – types arg. Default Empty set
- property default: object
Default Value
- Getter
Gets default value
- Setter
Sets default value
- property field: Optional[str]
Field Value
- Getter
Gets field value
- Setter
Sets field value
- property key: str
Key Value
- Getter
Gets Key Value
- Setter
Sets key value
- property require: bool
Require Value
- Getter
Gets require value
- Setter
Sets require value
- property rules_all: List[Callable[[kwhelp.rules.IRule], bool]]
Rules values
- Getter
Gets rules_all
- Setter
Sets rules_all
- property rules_any: List[Callable[[kwhelp.rules.IRule], bool]]
Rules values
- Getter
Gets rules_any
- Setter
Sets rules_any
- property types: Set[type]
Types values
- Getter
Gets types values
- Setter
Sets types values
KwArg Class
- class kwhelp.KwArg(**kwargs)[source]
Class for assigning kwargs to autogen fields with type checking and testing
- __init__(**kwargs)[source]
Constructor
- Keyword Arguments
kwargs (dict) – dictionary of args
Example
from kwhelp import KwArg def my_method(**kwargs) -> str: kw = KwArg(**kwargs) # assign args kw.kw_assign(key='first', require=True, types=[int]) kw.kw_assign(key='second', require=True, types=[int]) kw.kw_assign(key='msg', types=[str], default='Result:') kw.kw_assign(key='end', types=[str]) _result = kw.first + kw.second if kw.is_attribute_exist('end'): return_msg = f'{kw.msg} {_result}{kw.end}' else: return_msg = f'{kw.msg} {_result}' return return_msg
- is_attribute_exist(attrib_name: str) bool[source]
Gets if
attrib_nameexist the current instance.Use this method when:
When assigning a key that is not required it may not exist in the current instance.
When assing key that are required then the field will exist in the current instance.
- Parameters
attrib_name (str) – This is usually the
keyvalue ofkw_assign()orfieldvalue ofkw_assign().- Returns
Trueifattrib_nameexist in current instance; Otherwise,False.- Return type
bool
- is_key_existing(key: str) bool[source]
Gets if the key exist in current kwargs. Basically shortcut for key in kwargs
- kw_assign(key: str, field: Optional[str] = None, require: bool = False, default: Optional[object] = <kwhelp.helper.NoThing object>, types: Optional[List[type]] = None, rules_all: Optional[List[Callable[[kwhelp.rules.IRule], bool]]] = None, rules_any: Optional[List[Callable[[kwhelp.rules.IRule], bool]]] = None) bool[source]
Assigns attribute value to current instance passed in to constructor. Attributes automatically.
- Parameters
key (str) – the key of the key, value pair that is required or optional in
kwargspassed into to constructor.all_rules (bool, optional) – Determines if all rules or any rules are to be matched. If
Truethen all rules included inrulesmust be valid to be considered a success. IfFalsethen any rule included inrulesthat is valid is considered a success. DefaultFalse.field (str, optional) –
the name of the field to assign a value. if
fieldis omitted then field name is built usingkey. If included thenkwargs_helper.field_prefixwill be ignored. Defaults to Empty string.See also: Kw_assign field,
KwArg.kwargs_helperrequire (bool, optional) –
Determins if
keyis required to be in kwargs passed into to constructor. ifdefaultis passed in thenrequireis ignored. Defaults toFalse.See also: Kw_assign Require Arg
default (object, optional) –
default value to assign to key attribute if no value is found in
kwargspassed into to constructor. Ifdefaultis passed in thenrequireis ignored. Defaults toNO_THING.See also: Kw_assign Default Value
types (List[type], optional) –
a type list of one or more types that the value of the key value pair must match. For example if a value is required to be only
strthentypes=[str]. In this example if value is not typestrthenTypeErroris raised If value is required to be str or int thentypes=[str, int]. Defaults toNone.See also: Kw_assign Type Checking
rules_all (List[Callable[[IRule], bool]], optional) –
List of rules that must be passed before assignment can take place. If
typesis included thentypestakes priority over this arg. All rules must validate asTruebefore assignment takes place. Defaults toNone.See also: Kw_assign Rule Checking
rules_any (List[Callable[[IRule], bool]], optional) –
List of rules that must be passed before assignment can take place. If
typesis included thentypestakes priority over this arg. Any rule that validates asTrueresults in assignment taking place. Defaults toNone.See also: Kw_assign Rule Checking
- Raises
RuleError – If
kwargs_helper.rule_errorisTrueand Validation ofrules_allorrules_anyfails.TypeError – If validation of
typesfails.ReservedAttributeError – if
keyis a reserved keywordReservedAttributeError – if
fieldis a reserved keyword
- Returns
Trueif attribute assignment is successful; Otherwise,False- Return type
bool
- property kw_unused_keys: Set[str]
Gets any unused keys passed into constructor via
**kwargsThis would be a set of keys that were never used passed into the constructor.
- property kwargs_helper: kwhelp.KwargsHelper
Get instance of KwargsHelper used to add fields current instance
KwargsHelper Class
- class kwhelp.KwargsHelper(originator: object, obj_kwargs: dict, **kwargs)[source]
kwargs helper class. Assigns attributes to class with various checks
Example
class MyClass: def __init__(self, **kwargs): self._msg = '' kw = KwargsHelper(self, {**kwargs}) kw.assign(key='msg', require=True, types=['str']) kw.assign(key='length', types=['int'], default=-1) @property def msg(self) -> str: return self._msg @property def length(self) -> str: return self._length
>>> my_class = MyClass(msg='Hello World') >>> print(my_class.msg) Hello World >>> print(my_class.length) -1
- __init__(originator: object, obj_kwargs: dict, **kwargs)[source]
Constructor
- Parameters
originator (object) – object that attributes are assigned to via
assign()method. This is usually a class.obj_kwargs (dict) – The dictionary of key value args used to set values of attributes. Often passed in as
obj_kwargs = {**kwargs}
- Keyword Arguments
field_prefix (str, optional) – sets the
field_prefixproperty. Default_.name (str, optional) – sets the field_prefix property. Default is the name of
originatorobject.cancel_error (bool, optional) – sets the cancel_error property. Default
True.rule_error (bool, optional) – sets the
rule_errorproperty. DefaultTrue.assign_true_not_required (bool, optional) – sets the
assign_true_not_requiredproperty. DefaultTrue.type_instance_check (bool, optional) – If
TrueandKwargsHelper.assign`()argtypesis set then values will be tested also for isinstance rather then just type check if type check isFalse. IfFalsethen values willl only be tested as type. DefaultTrue
- Raises
TypeError – if any arg is not of the correct type.
- add_handler_after_assign(callback: Callable[[kwhelp.KwargsHelper, kwhelp.AfterAssignEventArgs], None])[source]
Add handler afer assign
- Parameters
callback (Callable[['KwargsHelper', AfterAssignEventArgs], None]) – Callback Method
See also
- add_handler_after_assign_auto(callback: Callable[[kwhelp.KwargsHelper, kwhelp.AfterAssignAutoEventArgs], None])[source]
Adds handler for after assign auto
- Parameters
callback (Callable[['KwargsHelper', AfterAssignAutoEventArgs], None]) – Callback Method
See also
- add_handler_before_assign(callback: Callable[[kwhelp.KwargsHelper, kwhelp.BeforeAssignEventArgs], None])[source]
Add handler before assign
- Parameters
callback (Callable[['KwargsHelper', BeforeAssignEventArgs], None]) – Callback Method
See also
- add_handler_before_assign_auto(callback: Callable[[kwhelp.KwargsHelper, kwhelp.BeforeAssignAutoEventArgs], None])[source]
Adds handler for before assigne auto
- Parameters
callback (Callable[['KwargsHelper', BeforeAssignAutoEventArgs], None]) – Callback Method
See also
- assign(key: str, field: Optional[str] = None, require: bool = False, default: Optional[object] = <kwhelp.helper.NoThing object>, types: Optional[Iterable[type]] = None, rules_all: Optional[Iterable[Callable[[kwhelp.rules.IRule], bool]]] = None, rules_any: Optional[Iterable[Callable[[kwhelp.rules.IRule], bool]]] = None) bool[source]
Assigns attribute value to
objpassed in to constructor. Attributes are created if they do not exist.- Parameters
key (str) – the key of the key, value pair that is required or optional in
obj_kwargspassed into to constructor.field (str, optional) –
the name of the field to assign a value. If
fieldis omitted then field name is built usinginstance.field_prefix+key. If included theninstance.field_prefixwill be ignored. Defaults toNone.See also: Assign Field Value
require (bool, optional) –
Determins if
keyis required to be inobj_kwargspassed into to constructor. ifdefaultis passed in thenrequireis ignored. Defaults toFalse.See also: Assign Require Arg
default (object, optional) –
default value to assign to key attribute if no value is found in
obj_kwargspassed into to constructor. Ifdefaultis passed in thenrequireis ignored. Defaults toNO_THINGwhich will result in default being ignored.See also: Assign Default Value
types (Iterable[type], optional) –
a type list of one or more types that the value of the key value pair must match. For example if a value is required to be only
strthentypes=[str]. If value is required to bestrorintthentypes=[str, int]. In this example if value is not typestrthenTypeErroris raised. Iftypesis omitted then a value can be any type unless there is a rule inrulesthat is otherwise. Defaults toNone.See also: Assign Type Checking
rules_all (Iterable[Callable[[IRule], bool]], optional) –
List of rules that must be passed before assignment can take place. If
typesis included thentypestakes priority over this arg. All rules must validate asTruebefore assignment takes place. Defaults toNone.See also: Assign Rule Checking
rules_any (Iterable[Callable[[IRule], bool]], optional) –
List of rules that must be passed before assignment can take place. If
typesis included thentypestakes priority over this arg. Any rule that validates asTrueresults in assignment taking place. Defaults toNone.See also: Assign Rule Checking
- Returns
Trueif attribute assignment is successful; Otherwise,False- Return type
bool
- Raises
RuleError – If
rule_errorisTrueand Validation ofrules_allorrules_anyfails.TypeError – If validation of
typesfails.
- assign_helper(helper: kwhelp.HelperArgs) bool[source]
Assigns attribute value using instance of HelperArgs. See
assign()method.- Parameters
helper (HelperArgs) – instance to assign.
- Returns
Trueif attribute assignment is successful; Otherwise,False.- Return type
bool
- auto_assign(types: Optional[Iterable[type]] = None, rules_all: Optional[Iterable[Callable[[kwhelp.rules.IRule], bool]]] = None, rules_any: Optional[Iterable[Callable[[kwhelp.rules.IRule], bool]]] = None) bool[source]
Assigns all of the key, value pairs of
obj_kwargspassed into constructor tooriginator, unless the event is canceled inBeforeAssignAutoEventArgsthen key, value pair will be added automacally tooriginator.- Parameters
types (Iterable[type], optional) –
a type list of one or more types that the value of the key value pair must match. For example if all values are required to be only
strthentypes=[str]. If all values are required to bestrorintthentypes=[str, int].If
typesis omitted then values can be any type unless there is a rule inrulesthat is otherwise. Defaults toNone.See also: Assign Type Checking
rules_all (Iterable[Callable[[IRule], bool]], optional) –
List of rules that must be passed before assignment can take place. If
typesis included thentypestakes priority over this arg. All rules must validate asTruebefore assignment takes place. Defaults toNone.See also: Assign Rule Checking
rules_any (Iterable[Callable[[IRule], bool]], optional) –
List of rules that must be passed before assignment can take place. If
typesis included thentypestakes priority over this arg. Any rule that validates asTrueresults in assignment taking place. Defaults toNone.See also: Assign Rule Checking
- Returns
Trueof all key, value pairs are added; Otherwise,False.- Return type
bool
- Raises
RuleError – If
rule_errorisTrueand Validation of rules fails.TypeError – If validation of
typesfails.
Note
Call back events are supported via
add_handler_before_assign_auto()andadd_handler_after_assign_auto()methods.
- is_key_existing(key: str) bool[source]
Gets if the key exist in kwargs dictionary passed in to the constructor by
obj_kwargsarg.- Parameters
key (str) – Key value to check for existance.
- Returns
Trueifkeyexist; Otherwise,False.- Return type
bool
- property assign_true_not_required: bool
Determines
assign_true_not_requiredOption. IfTruethen and a non-required arg is assigned viaassign(). thenassign()returnsTrueeven if the arg failed to be applied. In anafter callbackmethod set byadd_handler_after_assign()success inAfterAssignEventArgs.successproperty isFalseif arg was not assigned. DefaultTrue- Getter
Gets option value.
- Setter
Sets option value.
- property cancel_error: bool
Determins if an error will be raised if cancel is set in
BeforeAssignEventArgsof a callback. DefaultTrue.- Getter
Gets cancel_error option.
- Setter
Sets cancel_error option.
- property field_prefix: str
Determines the field prefix option. The prefix use when setting attributes: Default:
_. To add args without a prefix set the valuefield_prefix = ''This parameter is ignored whenfieldis used inassign()method such as:assign(msg='hi', field='message')- Getter
Gets the field prefix option.
- Setter
Sets the field prefix option.
- property kw_args: Dict[str, Any]
Gets the kwargs dictionary passed in to the constructor by
obj_kwargsarg
- property name: str
Determins name option.
namethat represents theoriginatorin error messages. Default:type(originator)__name__- Getter
Gets name option.
- Setter
Sets name option
- property originator: object
Gets originator option
object that attributes are assigned to via
assign()method. This is usually a class.
- property rule_error: bool
Determins rule_error option. Default
True- Getter
Gets rule_error option.
- Setter
Sets rule_error option.
- property rule_test_before_assign: bool
Determines rule_test_before_assign option. If
Truerule testing will occur before assign value to attribute. IfTrueandrule_errorisTruethen rule errors will prevent assigning value. IfFalsethen attribute values will be assigned even if rules does not validate. Validation can still fail and errors can still be raised, except now the validation will take place after attribute value has been assigned. Default:True- Getter
Gets rule_test_before_assign option.
- Setter
Sets rule_test_before_assign option.
- property unused_keys: Set[str]
Gets any unused keys passed into constructor via
obj_kwargsThis would be a set of keys that were never used passed into the constructor.
Helper Module
- class kwhelp.helper.Formatter[source]
String Fromat Methods
- static get_formated_names(names: List[str], **kwargs) str[source]
Gets a formated string of a list of names
- Parameters
names (List[str]) – List of names
- Keyword Arguments
conj (str, optional) – Conjunction used to join list. Default
and.wrapper (str, optional) – String to prepend and append to each value. Default
'.
- Returns
formated such as
'final' and 'end'or'one', 'final', and 'end'- Return type
str
- static get_formated_types(types: Iterator[type], **kwargs) str[source]
Gets a formated string from a list of types.
- Parameters
types (Iterator[type]) – Types to create fromated string.
- Keyword Arguments
conj (str, optional) – Conjunction used to join list. Default
and.wrapper (str, optional) – String to prepend and append to each value. Default
'.
- Returns
Formated String
- Return type
str
- static get_missing_args_error_msg(missing_names: List[str], name: Optional[str] = '')[source]
Get an error message for a list of names.
- Parameters
missing_names (List[str]) – List of names that generated the error. Such as a list of missing arguments of a function.
name (Optional[str], optional) – Function, class, method name. Defaults to “”.
- Returns
Formated string for
missing_nameshas elements; Otherwise, empty string is returned.- Return type
[type]
- static get_ordinal(num: int) str[source]
Returns the ordinal number of a given integer, as a string.
- Parameters
num (int) – integer to get ordinal value of.
- Returns
num as ordinal str. eg. 1 -> 1st, 2 -> 2nd, 3 -> 3rd, etc.
- Return type
str
- kwhelp.helper.is_iterable(arg: object, excluded_types: Iterable[type] = (<class 'str'>, )) bool[source]
Gets if
argis iterable.- Parameters
arg (object) – object to test
excluded_types (Iterable[type], optional) – Iterable of type to exlcude. If
argmatches any type inexcluded_typesthenFalsewill be returned. Default(str,)
- Returns
Trueifargis an iterable object and not of a type inexcluded_types; Otherwise,False.- Return type
bool
Note
if
argis of type str then return result isFalse.Example
# non-string iterables assert is_iterable(arg=("f", "f")) # tuple assert is_iterable(arg=["f", "f"]) # list assert is_iterable(arg=iter("ff")) # iterator assert is_iterable(arg=range(44)) # generator assert is_iterable(arg=b"ff") # bytes (Python 2 calls this a string) # strings or non-iterables assert not is_iterable(arg=u"ff") # string assert not is_iterable(arg=44) # integer assert not is_iterable(arg=is_iterable) # function # excluded_types, optionally exlcude types from enum import Enum, auto class Color(Enum): RED = auto() GREEN = auto() BLUE = auto() assert is_iterable(arg=Color) # Enum assert not is_iterable(arg=Color, excluded_types=(Enum, str)) # Enum
- kwhelp.helper.NO_THING = <kwhelp.helper.NoThing object>
Singleton Class instance that represents null object.
checks
RuleChecker Class
- class kwhelp.checks.RuleChecker(rules_all: Optional[Iterable[kwhelp.rules.IRule]] = None, rules_any: Optional[Iterable[kwhelp.rules.IRule]] = None, **kwargs)[source]
Class that validates args match a given rule
- __init__(rules_all: Optional[Iterable[kwhelp.rules.IRule]] = None, rules_any: Optional[Iterable[kwhelp.rules.IRule]] = None, **kwargs)[source]
Constructor
- Parameters
- Keyword Arguments
raise_error (bool, optional) – If
Truethen rules can raise errors when validation fails. DefaultFalse.- Raises
TypeError – If
rule_allis not an iterable objectTypeError – If
rule_anyis not an iterable object
- validate_all(*args, **kwargs) bool[source]
Validates all. All
*argsand**kwargsmust matchrules_all- Returns
Trueif all*argsand**kwargsare valid; Otherwise,False- Return type
bool
- Raises
Exception – If
raise_errorisTrueand validation Fails. The type of exception raised is dependend on theIRulethat caused validation failure. Most rules raise aValueErroror aTypeError.
- validate_any(*args, **kwargs) bool[source]
Validates any. All
*argsand**kwargsmust match on ore more ofrules_any- Returns
Trueif all*argsand**kwargsare valid; Otherwise,False- Return type
bool
- Raises
Exception – If
raise_errorisTrueand validation Fails. The type of exception raised is dependend on theIRulethat caused validation failure. Most rules raise aValueErroror aTypeError.
- property raise_error: bool
Determines if errors will be raised during validation
If
Truethen errors will be raised when validation fails. Default value isTrue.- Getter
Gets if errors can be raised.
- Setter
Sets if errors can be raised.
- property rules_all: Iterable[kwhelp.rules.IRule]
Gets rules passed into
rules_allof constructor used for validation of args.
- property rules_any: Iterable[kwhelp.rules.IRule]
Gets rules passed into
rules_anyof constructor used for validation of args.
SubClassChecker Class
- class kwhelp.checks.SubClassChecker(*args: type, **kwargs)[source]
Class that validates args is a subclass of a give type
- __init__(*args: type, **kwargs)[source]
Constructor
- Other Arguments:
args (type): One or more types used for Validation purposes.
- Keyword Arguments
raise_error (bool, optional) – If
Truethen an error will be raised if avalidate()fails: Othwewisevalidate()will return a boolean value indicationg success or failure. DefaultTrueopt_inst_only (bool, optional) – If
Truethen validation will requires all values being tested to be an instance of a class. IfFalsevaladition will test class instance and class type. DefaultTrue
- validate(*args, **kwargs) bool[source]
Validates all
*argsand all**kwargsagainsttypesthat are passed into constructor.- Returns
Trueif all*argsand all**kwargmatch a valid class; Otherwise;False.- Return type
bool
- Raises
TypeError – if
raise_errorisTrueand validation fails.
- property instance_only: bool
Determines if validation requires instance of class
If
Truethen validation will fail when a type is validated, rather then an instance of a class.- Getter
Gets instance_only.
- Setter
Sets instance_only.
- property raise_error: bool
Determines if errors will be raised during validation
If
Truethen errors will be raised when validation fails.- Getter
Gets if errors can be raised.
- Setter
Sets if errors can be raised.
- property types: Tuple[type]
Gets the types passed into constructor that are used for validating args
TypeChecker Class
- class kwhelp.checks.TypeChecker(*args: type, **kwargs)[source]
Class that validates args match a given type
- __init__(*args: type, **kwargs)[source]
Constructor
- Other Arguments:
args (type): One or more types used for Validation purposes.
- Keyword Arguments
raise_error (bool, optional) – If
Truethen an error will be raised if avalidate()fails: Othwewisevalidate()will return a boolean value indicationg success or failure. DefaultTruetype_instance_check (bool, optional) – If
Truethenvalidate()args are tested also for isinstance if type does not match, rather then just type check if type is a match. IfFalsethen values willl only be tested as type. DefaultTrue
- validate(*args, **kwargs) bool[source]
Validates all
*argsand all**kwargsagainsttypesthat are passed into constructor.- Returns
Trueif all*argsand all**kwargmatch a type; Otherwise;False.- Return type
bool
- Raises
TypeError – if
raise_errorisTrueand validation fails.
- property raise_error: bool
Determines if errors will be raised during validation
If
Truethen errors will be raised when validation fails.- Getter
Gets if errors can be raised.
- Setter
Sets if errors can be raised.
- property type_instance_check: bool
Determines if instance checking is done with type checking.
If
Truethenvalidate`()args are tested also for isinstance if type does not match, rather then just type check if type is a match. IfFalsethen values willl only be tested as type.- Getter
Gets type_instance_check value
- Setter
Sets type_instance_check value
- property types: Tuple[type]
Gets the types passed into constructor that are used for validating args
decorator
AcceptedTypes Class
- class kwhelp.decorator.AcceptedTypes(*args: Union[type, Iterable[type]], **kwargs)[source]
Decorator that decorates methods that requires args to match types specificed in a list
See also
- __init__(*args: Union[type, Iterable[type]], **kwargs)[source]
Constructor
- Parameters
args (Union[type, Iterable[type]]) – One or more types or Iterator[type] for validation.
- Keyword Arguments
type_instance_check (bool, optional) – If
Truethen args are tested also forisinstance()if type does not match, rather then just type check. IfFalsethen values willl only be tested as type. DefaultTrueftype (DecFuncType, optional) – Type of function that decorator is applied on. Default
DecFuncType.FUNCTIONopt_return (object, optional) – Return value when decorator is invalid. By default an error is rasied when validation fails. If
opt_returnis supplied then it will be return when validation fails and no error will be raised.opt_all_args (bool, optional) – If
Truethen the last subclass type passed into constructor will define any remaining args. This allows for one subclass to define required match of all arguments that decorator is applied to. DefaultFalseopt_args_filter (DecArgEnum, optional) – Filters the arguments that are validated. Default
DecArgEnum.ALL.opt_logger (Union[Logger, LoggerAdapter], optional) – Logger that logs exceptions when validation fails.
ArgsLen Class
- class kwhelp.decorator.ArgsLen(*args: Union[type, Iterable[type]], **kwargs)[source]
Decorartor that sets the number of args that can be added to a function
- Raises
ValueError – If wrong args are passed into construcor.
ValueError – If validation of arg count fails.
See also
- __init__(*args: Union[type, Iterable[type]], **kwargs)[source]
Constructor
- Parameters
args (Union[int, iterable[int]]) –
One or more int or Iterator[int] for validation.
Single
intvalues are to match exact.iterable[int]must be a pair ofintwith the firstintless then the secondint.
- Keyword Arguments
ftype (DecFuncType, optional) – Type of function that decorator is applied on. Default
DecFuncType.FUNCTIONopt_return (object, optional) – Return value when decorator is invalid. By default an error is rasied when validation fails. If
opt_returnis supplied then it will be return when validation fails and no error will be raised.opt_logger (Union[Logger, LoggerAdapter], optional) – Logger that logs exceptions when validation fails.
ArgsMinMax Class
- class kwhelp.decorator.ArgsMinMax(min: Optional[int] = 0, max: Optional[int] = None, **kwargs)[source]
Decorartor that sets the min and or max number of args that can be added to a function
See also
- __init__(min: Optional[int] = 0, max: Optional[int] = None, **kwargs)[source]
Constructor
- Parameters
min (int, optional) – Min number of args for a function. Defaults to 0.
max (int, optional) – Max number of args for a function. Defaults to None.
- Keyword Arguments
ftype (DecFuncType, optional) – Type of function that decorator is applied on. Default
DecFuncType.FUNCTIONopt_return (object, optional) – Return value when decorator is invalid. By default an error is rasied when validation fails. If
opt_returnis supplied then it will be return when validation fails and no error will be raised.opt_logger (Union[Logger, LoggerAdapter], optional) – Logger that logs exceptions when validation fails.
AutoFill Class
- class kwhelp.decorator.AutoFill(*args, **kwargs)[source]
Class decorator that replaces the
__init__function with one that sets instance attributes with the specified argument names and default values. The original__init__is called with no arguments after the instance attributes have been assigned.Example
>>> @AutoFill('a', 'b', c=3) ... class Foo: pass >>> sorted(Foo(1, 2).__dict__.items()) [('a', 1), ('b', 2), ('c', 3)]
AutoFillKw Class
- class kwhelp.decorator.AutoFillKw(cls)[source]
Class decorator that replaces the
__init__function with one that sets instance attributes with the specified key, value ofkwargs. The original__init__is called with any*argsafter the instance attributes have been assigned.Example
>>> @AutoFillKw ... class Foo: pass >>> sorted(Foo(a=1, b=2, End="!").__dict__.items()) [('End', '!'), ('a', 1), ('b', 2)]
DecArgEnum
DecFuncEnum
- class kwhelp.decorator.DecFuncEnum(value)[source]
Represents options for type of Function or Method
- FUNCTION = 1
Normal Unbound function
- METHOD = 3
Class Method
- METHOD_CLASS = 4
Class Method (@classmethod)
- METHOD_STATIC = 2
Class Static Method (@staticmethod)
- PROPERTY_CLASS = 5
Class Property (@property)
DefaultArgs Class
RequireArgs Class
- class kwhelp.decorator.RequireArgs(*args: str, **kwargs)[source]
Decorator that defines required args for
**kwargsof a function.See also
- __init__(*args: str, **kwargs)[source]
Constructor
- Parameters
args (type) – One or more names of wrapped function args to require.
- Keyword Arguments
ftype (DecFuncType, optional) – Type of function that decorator is applied on. Default
DecFuncType.FUNCTIONopt_return (object, optional) – Return value when decorator is invalid. By default an error is rasied when validation fails. If
opt_returnis supplied then it will be return when validation fails and no error will be raised.opt_logger (Union[Logger, LoggerAdapter], optional) – Logger that logs exceptions when validation fails.
ReturnRuleAll Class
- class kwhelp.decorator.ReturnRuleAll(*args: kwhelp.rules.IRule, **kwargs)[source]
Decorator that decorates methods that require return value to match all rules specificed.
See also
- __init__(*args: kwhelp.rules.IRule, **kwargs)[source]
Constructor
- Parameters
args (IRule) – One or more rules to use for validation
- Keyword Arguments
ftype (DecFuncType, optional) – Type of function that decorator is applied on. Default
DecFuncType.FUNCTIONDefaultTrueopt_return (object, optional) – Return value when decorator is invalid. By default an error is rasied when validation fails. If
opt_returnis supplied then it will be return when validation fails and no error will be raised.opt_logger (Union[Logger, LoggerAdapter], optional) – Logger that logs exceptions when validation fails.
ReturnRuleAny Class
- class kwhelp.decorator.ReturnRuleAny(*args: kwhelp.rules.IRule, **kwargs)[source]
Decorator that decorates methods that require return value to match any of the rules specificed.
See also
- __init__(*args: kwhelp.rules.IRule, **kwargs)[source]
Constructor
- Parameters
args (IRule) – One or more rules to use for validation
- Keyword Arguments
ftype (DecFuncType, optional) – Type of function that decorator is applied on. Default
DecFuncType.FUNCTIONopt_return (object, optional) – Return value when decorator is invalid. By default an error is rasied when validation fails. If
opt_returnis supplied then it will be return when validation fails and no error will be raised.opt_logger (Union[Logger, LoggerAdapter], optional) – Logger that logs exceptions when validation fails.
ReturnType Class
- class kwhelp.decorator.ReturnType(*args: type, **kwargs)[source]
Decorator that decorates methods that require return value to match a type specificed.
See also
- __init__(*args: type, **kwargs)[source]
Constructor
- Parameters
args (type) – One ore more types that is used to validate return type.
- Keyword Arguments
type_instance_check (bool, optional) – If
Truethen args are tested also forisinstance()if type does not match, rather then just type check. IfFalsethen values willl only be tested as type. DefaultTrueopt_return (object, optional) – Return value when decorator is invalid. By default an error is rasied when validation fails. If
opt_returnis supplied then it will be return when validation fails and no error will be raised.opt_logger (Union[Logger, LoggerAdapter], optional) – Logger that logs exceptions when validation fails.
RuleCheckAll Class
- class kwhelp.decorator.RuleCheckAll(*args: kwhelp.rules.IRule, **kwargs)[source]
Decorator that decorates methods that require args to match all rules specificed in
ruleslist.If a function arg does not match all rules in
ruleslist then validation will fail.See also
- __init__(*args: kwhelp.rules.IRule, **kwargs)[source]
Constructor
- Parameters
args (IRule) – One or more rules to use for validation
- Keyword Arguments
raise_error (bool, optional) –
If
Truethen an Exception will be raised if a validation fails. The kind of exception raised depends on the rule that is invalid. Typically aTypeErroror aValueErroris raised.If
Falsethen an attribute will be set on decorated function namedis_rules_all_validindicating if validation status. DefaultTrue.ftype (DecFuncType, optional) – Type of function that decorator is applied on. Default
DecFuncType.FUNCTIONopt_return (object, optional) – Return value when decorator is invalid. By default an error is rasied when validation fails. If
opt_returnis supplied then it will be return when validation fails and no error will be raised.opt_args_filter (DecArgEnum, optional) – Filters the arguments that are validated. Default
DecArgEnum.ALL.opt_logger (Union[Logger, LoggerAdapter], optional) – Logger that logs exceptions when validation fails.
RuleCheckAllKw Class
- class kwhelp.decorator.RuleCheckAllKw(arg_info: Dict[str, Union[int, kwhelp.rules.IRule, Iterable[kwhelp.rules.IRule]]], rules: Optional[Iterable[Union[kwhelp.rules.IRule, Iterable[kwhelp.rules.IRule]]]] = None, **kwargs)[source]
Decorator that decorates methods that require specific args to match rules specificed in
ruleslist.If a function specific args do not match all matching rules in
ruleslist then validation will fail.See also
- __init__(arg_info: Dict[str, Union[int, kwhelp.rules.IRule, Iterable[kwhelp.rules.IRule]]], rules: Optional[Iterable[Union[kwhelp.rules.IRule, Iterable[kwhelp.rules.IRule]]]] = None, **kwargs)[source]
Constructor
- Parameters
arg_info (Dict[str, Union[int, IRule, Iterable[IRule]]]) – Dictionary of Key and int, IRule, or Iterable[IRule]. Each Key represents that name of an arg to check with one or more rules. If value is int then value is an index that corresponds to an item in
rules.rules (Iterable[Union[IRule, Iterable[IRule]]], optional) – List of rules for arg_info entries to match. Default
None
- Keyword Arguments
raise_error (bool, optional) –
If
Truethen an Exception will be raised if a validation fails. The kind of exception raised depends on the rule that is invalid. Typically aTypeErroror aValueErroris raised.If
Falsethen an attribute will be set on decorated function namedis_rules_kw_all_validindicating if validation status. DefaultTrue.ftype (DecFuncType, optional) – Type of function that decorator is applied on. Default
DecFuncType.FUNCTIONopt_return (object, optional) – Return value when decorator is invalid. By default an error is rasied when validation fails. If
opt_returnis supplied then it will be return when validation fails and no error will be raised.opt_logger (Union[Logger, LoggerAdapter], optional) – Logger that logs exceptions when validation fails.
RuleCheckAny Class
- class kwhelp.decorator.RuleCheckAny(*args: kwhelp.rules.IRule, **kwargs)[source]
Decorator that decorates methods that require args to match a rule specificed in
ruleslist.If a function arg does not match at least one rule in
ruleslist then validation will fail.See also
- __init__(*args: kwhelp.rules.IRule, **kwargs)[source]
Constructor
- Parameters
args (IRule) – One or more rules to use for validation
- Keyword Arguments
raise_error (bool, optional) –
If
Truethen an Exception will be raised if a validation fails. The kind of exception raised depends on the rule that is invalid. Typically aTypeErroror aValueErroris raised.If
Falsethen an attribute will be set on decorated function namedis_rules_any_validindicating if validation status. DefaultTrue.ftype (DecFuncType, optional) – Type of function that decorator is applied on. Default
DecFuncType.FUNCTIONopt_return (object, optional) – Return value when decorator is invalid. By default an error is rasied when validation fails. If
opt_returnis supplied then it will be return when validation fails and no error will be raised.opt_args_filter (DecArgEnum, optional) – Filters the arguments that are validated. Default
DecArgEnum.ALL.opt_logger (Union[Logger, LoggerAdapter], optional) – Logger that logs exceptions when validation fails.
RuleCheckAnyKw Class
- class kwhelp.decorator.RuleCheckAnyKw(arg_info: Dict[str, Union[int, kwhelp.rules.IRule, Iterable[kwhelp.rules.IRule]]], rules: Optional[Iterable[Union[kwhelp.rules.IRule, Iterable[kwhelp.rules.IRule]]]] = None, **kwargs)[source]
Bases:
kwhelp.decorator.RuleCheckAllKwDecorator that decorates methods that require specific args to match rules specificed in
ruleslist.If a function specific args do not match at least one matching rule in
ruleslist then validation will fail.See also
- __init__(arg_info: Dict[str, Union[int, kwhelp.rules.IRule, Iterable[kwhelp.rules.IRule]]], rules: Optional[Iterable[Union[kwhelp.rules.IRule, Iterable[kwhelp.rules.IRule]]]] = None, **kwargs)
Constructor
- Parameters
arg_info (Dict[str, Union[int, IRule, Iterable[IRule]]]) – Dictionary of Key and int, IRule, or Iterable[IRule]. Each Key represents that name of an arg to check with one or more rules. If value is int then value is an index that corresponds to an item in
rules.rules (Iterable[Union[IRule, Iterable[IRule]]], optional) – List of rules for arg_info entries to match. Default
None
- Keyword Arguments
raise_error (bool, optional) –
If
Truethen an Exception will be raised if a validation fails. The kind of exception raised depends on the rule that is invalid. Typically aTypeErroror aValueErroris raised.If
Falsethen an attribute will be set on decorated function namedis_rules_kw_all_validindicating if validation status. DefaultTrue.ftype (DecFuncType, optional) – Type of function that decorator is applied on. Default
DecFuncType.FUNCTIONopt_return (object, optional) – Return value when decorator is invalid. By default an error is rasied when validation fails. If
opt_returnis supplied then it will be return when validation fails and no error will be raised.opt_logger (Union[Logger, LoggerAdapter], optional) – Logger that logs exceptions when validation fails.
- property args: Iterable[object]
Gets/sets wrapped function args
- property fn_cache: Dict[str, object]
Gets function level cache
- property kwargs: Dict[str, Any]
Gets/sets wrapped function kwargs
SubClass Class
- class kwhelp.decorator.SubClass(*args: Union[type, Iterable[type]], **kwargs)[source]
Decorator that requires args of a function to match or be a subclass of types specificed in constructor.
See also
- __init__(*args: Union[type, Iterable[type]], **kwargs)[source]
Constructor
- Parameters
args (Union[type, Iterable[type]]) – One or more types or Iterator[type] for validation.
- Keyword Arguments
type_instance_check (bool, optional) – If
Truethen args are tested also forisinstance()if type does not match, rather then just type check. IfFalsethen values willl only be tested as type. DefaultTrueftype (DecFuncType, optional) – Type of function that decorator is applied on. Default
DecFuncType.FUNCTIONopt_return (object, optional) – Return value when decorator is invalid. By default an error is rasied when validation fails. If
opt_returnis supplied then it will be return when validation fails and no error will be raised.opt_inst_only (bool, optional) – If
Truethen validation will requires all values being tested to be an instance of a class. IfFalsevaladition will test class instance and class type. DefaultTrueopt_all_args (bool, optional) – If
Truethen the last subclass type passed into constructor will define any remaining args. This allows for one subclass to define required match of all arguments that decorator is applied to. DefaultFalseopt_args_filter (DecArgEnum, optional) – Filters the arguments that are validated. Default
DecArgEnum.ALL.opt_logger (Union[Logger, LoggerAdapter], optional) – Logger that logs exceptions when validation fails.
SubClasskKw Class
- class kwhelp.decorator.SubClasskKw(arg_info: Dict[str, Union[int, type, Iterable[type]]], types: Optional[Iterable[Union[type, Iterable[type]]]] = None, **kwargs)[source]
Decorator that requires args of a function to match or be a subclass of types specificed in constructor.
See also
- __init__(arg_info: Dict[str, Union[int, type, Iterable[type]]], types: Optional[Iterable[Union[type, Iterable[type]]]] = None, **kwargs)[source]
Constructor
- Parameters
arg_info (Dict[str, Union[int, type, Iterable[type]]]) – Dictionary of Key and int, type, or Iterable[type]. Each Key represents that name of an arg to match one or more types(s). If value is int then value is an index that corresponds to an item in
types.types (Iterable[Union[type, Iterable[type]]], optional) – List of types for arg_info entries to match. Default
None
- Keyword Arguments
type_instance_check (bool, optional) – If
Truethen args are tested also forisinstance()if type does not match, rather then just type check. IfFalsethen values willl only be tested as type. DefaultTrueftype (DecFuncType, optional) – Type of function that decorator is applied on. Default
DecFuncType.FUNCTIONopt_return (object, optional) – Return value when decorator is invalid. By default an error is rasied when validation fails. If
opt_returnis supplied then it will be return when validation fails and no error will be raised.opt_logger (Union[Logger, LoggerAdapter], optional) – Logger that logs exceptions when validation fails.
TypeCheck Class
- class kwhelp.decorator.TypeCheck(*args: Union[type, Iterable[type]], **kwargs)[source]
Decorator that decorates methods that requires args to match a type specificed in a list
See also
- __init__(*args: Union[type, Iterable[type]], **kwargs)[source]
Constructor
- Parameters
args (type) – One or more types for wrapped function args to match.
- Keyword Arguments
raise_error – (bool, optional): If
Truethen aTypeErrorwill be raised if a validation fails. IfFalsethen an attribute will be set on decorated function namedis_types_validindicating if validation status. DefaultTrue.type_instance_check (bool, optional) – If
Truethen args are tested also forisinstance()if type does not match, rather then just type check. IfFalsethen values willl only be tested as type. DefaultTrueftype (DecFuncType, optional) – Type of function that decorator is applied on. Default
DecFuncType.FUNCTIONopt_return (object, optional) – Return value when decorator is invalid. By default an error is rasied when validation fails. If
opt_returnis supplied then it will be return when validation fails and no error will be raised.opt_args_filter (DecArgEnum, optional) – Filters the arguments that are validated. Default
DecArgEnum.ALL.opt_logger (Union[Logger, LoggerAdapter], optional) – Logger that logs exceptions when validation fails.
- Raises
TypeError – If
typesarg is not a iterable object such as a list or tuple.TypeError – If any arg is not of a type listed in
types.
TypeCheckKw Class
- class kwhelp.decorator.TypeCheckKw(arg_info: Dict[str, Union[int, type, Iterable[type]]], types: Optional[Iterable[Union[type, Iterable[type]]]] = None, **kwargs)[source]
Decorator that decorates methods that require key, value args to match a type specificed in a list
See also
- __init__(arg_info: Dict[str, Union[int, type, Iterable[type]]], types: Optional[Iterable[Union[type, Iterable[type]]]] = None, **kwargs)[source]
Constructor
- Parameters
arg_info (Dict[str, Union[int, type, Iterable[type]]]) – Dictionary of Key and int, type, or Iterable[type]. Each Key represents that name of an arg to match one or more types(s). If value is int then value is an index that corresponds to an item in
types.types (Iterable[Union[type, Iterable[type]]], optional) – List of types for arg_info entries to match. Default
None
- Keyword Arguments
raise_error – (bool, optional): If
Truethen aTypeErrorwill be raised if a validation fails. IfFalsethen an attribute will be set on decorated function namedis_types_kw_validindicating if validation status. DefaultTrue.type_instance_check (bool, optional) – If
Truethen args are tested also forisinstance()if type does not match, rather then just type check. IfFalsethen values willl only be tested as type. DefaultTrueftype (DecFuncType, optional) – Type of function that decorator is applied on. Default
DecFuncType.FUNCTIONopt_return (object, optional) – Return value when decorator is invalid. By default an error is rasied when validation fails. If
opt_returnis supplied then it will be return when validation fails and no error will be raised.opt_logger (Union[Logger, LoggerAdapter], optional) – Logger that logs exceptions when validation fails.
callcounter Decorator
Decorator method that adds call_count attribute to decorated method.
call_count is 0 if method has not been called.
call_count increases by 1 each time method is been called.
Note
This decorator needs to be the topmost decorator applied to a method
Example
>>> @callcounter
>>> def foo(msg):
>>> print(msg)
>>> print("Call Count:", foo.call_count)
0
>>> foo("Hello")
Hello
>>> print("Call Count:", foo.call_count)
1
>>> foo("World")
World
>>> print("Call Count:", foo.call_count)
2
See also
calltracker Decorator
Decorator method that adds has_been_called attribute to decorated method.
has_been_called is False if method has not been called.
has_been_called is True if method has been called.
Note
This decorator needs to be the topmost decorator applied to a method
Example
>>> @calltracker
>>> def foo(msg):
>>> print(msg)
>>> print(foo.has_been_called)
False
>>> foo("Hello World")
Hello World
>>> print(foo.has_been_called)
True
See also
singleton Decorator
Decorator that makes a class a singleton class
Example
@singleton
class Logger:
def log(self, msg):
print(msg)
logger1 = Logger()
logger2 = Logger()
assert logger1 is logger
See also
rules
IRule Class
- class kwhelp.rules.IRule(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Abstract Interface Class for rules
See also
- __init__(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Constructor
- Parameters
key (str) – the key that rule is to apply to.
name (str) – the name of the field that value was assigned
value (object) – the value that is assigned to
field_nameraise_errors (bool) – determinins if rule could raise an error when validation fails
originator (object) – the object that attributes validated for
- Raises
TypeError – If any arg is not of the correct type
- property field_name: str
Name of the field assigned.
- Getter
Gets the name of the field assigned
- Setter
Sets the name of the field assigned
- property field_value: object
The value assigned to
field_name- Getter
Gets value assigned to
field_name- Setter
Sets value assigned to
field_name
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes validated for
- property raise_errors: bool
Determines if a rule can raise an error when validation fails.
- Getter
Gets if a rule could raise an error when validation fails
- Setter
Sets if a rule could raise an error when validation fails
RuleAttrExist Class
- class kwhelp.rules.RuleAttrExist(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Bases:
kwhelp.rules.IRuleRule to ensure an attribute does exist before its value is set.
- __init__(key: str, name: str, value: object, raise_errors: bool, originator: object)
Constructor
- Parameters
key (str) – the key that rule is to apply to.
name (str) – the name of the field that value was assigned
value (object) – the value that is assigned to
field_nameraise_errors (bool) – determinins if rule could raise an error when validation fails
originator (object) – the object that attributes validated for
- Raises
TypeError – If any arg is not of the correct type
- validate() bool[source]
Validates that
field_nameis an existing attribute oforiginatorinstance.- Raises
AttributeError – If
raise_errorsisTrueandfield_nameis not an attribue oforiginatorinstance.- Returns
Trueiffield_nameis an existing attribue oforiginatorinstance; Otherwise,False.- Return type
bool
- property field_name: str
Name of the field assigned.
- Getter
Gets the name of the field assigned
- Setter
Sets the name of the field assigned
- property field_value: object
The value assigned to
field_name- Getter
Gets value assigned to
field_name- Setter
Sets value assigned to
field_name
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes validated for
- property raise_errors: bool
Determines if a rule can raise an error when validation fails.
- Getter
Gets if a rule could raise an error when validation fails
- Setter
Sets if a rule could raise an error when validation fails
RuleAttrNotExist Class
- class kwhelp.rules.RuleAttrNotExist(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Bases:
kwhelp.rules.IRuleRule to ensure an attribute does not exist before it is added to class.
- __init__(key: str, name: str, value: object, raise_errors: bool, originator: object)
Constructor
- Parameters
key (str) – the key that rule is to apply to.
name (str) – the name of the field that value was assigned
value (object) – the value that is assigned to
field_nameraise_errors (bool) – determinins if rule could raise an error when validation fails
originator (object) – the object that attributes validated for
- Raises
TypeError – If any arg is not of the correct type
- validate() bool[source]
Validates that
field_nameis not an existing attribute oforiginatorinstance.- Raises
AttributeError – If
raise_errorsisTrueandfield_nameis already an attribue oforiginatorinstance.- Returns
Trueiffield_nameis not an existing attribue oforiginatorinstance; Otherwise,False.- Return type
bool
- property field_name: str
Name of the field assigned.
- Getter
Gets the name of the field assigned
- Setter
Sets the name of the field assigned
- property field_value: object
The value assigned to
field_name- Getter
Gets value assigned to
field_name- Setter
Sets value assigned to
field_name
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes validated for
- property raise_errors: bool
Determines if a rule can raise an error when validation fails.
- Getter
Gets if a rule could raise an error when validation fails
- Setter
Sets if a rule could raise an error when validation fails
RuleBool Class
- class kwhelp.rules.RuleBool(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Bases:
kwhelp.rules.IRuleRule that matched only if value is instance of bool.
- __init__(key: str, name: str, value: object, raise_errors: bool, originator: object)
Constructor
- Parameters
key (str) – the key that rule is to apply to.
name (str) – the name of the field that value was assigned
value (object) – the value that is assigned to
field_nameraise_errors (bool) – determinins if rule could raise an error when validation fails
originator (object) – the object that attributes validated for
- Raises
TypeError – If any arg is not of the correct type
- validate() bool[source]
Validates that value to assign is a bool
- Raises
TypeError – If
raise_errorsisTrueandfield_valueis not instance of bool.- Returns
Trueiffield_valueis a bool; Otherwise,False.- Return type
bool
- property field_name: str
Name of the field assigned.
- Getter
Gets the name of the field assigned
- Setter
Sets the name of the field assigned
- property field_value: object
The value assigned to
field_name- Getter
Gets value assigned to
field_name- Setter
Sets value assigned to
field_name
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes validated for
- property raise_errors: bool
Determines if a rule can raise an error when validation fails.
- Getter
Gets if a rule could raise an error when validation fails
- Setter
Sets if a rule could raise an error when validation fails
RuleByteSigned Class
- class kwhelp.rules.RuleByteSigned(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Bases:
kwhelp.rules.RuleIntSigned Byte rule, range from
-128to127.- __init__(key: str, name: str, value: object, raise_errors: bool, originator: object)
Constructor
- Parameters
key (str) – the key that rule is to apply to.
name (str) – the name of the field that value was assigned
value (object) – the value that is assigned to
field_nameraise_errors (bool) – determinins if rule could raise an error when validation fails
originator (object) – the object that attributes validated for
- Raises
TypeError – If any arg is not of the correct type
- validate() bool[source]
Valids
- Raises
ValueError – If
raise_errorsisFalseand value is less then-128or greater than128.- Returns
Trueif Validation passes; Otherwise,False.- Return type
bool
- property field_name: str
Name of the field assigned.
- Getter
Gets the name of the field assigned
- Setter
Sets the name of the field assigned
- property field_value: object
The value assigned to
field_name- Getter
Gets value assigned to
field_name- Setter
Sets value assigned to
field_name
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes validated for
- property raise_errors: bool
Determines if a rule can raise an error when validation fails.
- Getter
Gets if a rule could raise an error when validation fails
- Setter
Sets if a rule could raise an error when validation fails
RuleByteUnsigned Class
- class kwhelp.rules.RuleByteUnsigned(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Bases:
kwhelp.rules.RuleIntUnsigned Byte rule, range from
0to255.- __init__(key: str, name: str, value: object, raise_errors: bool, originator: object)
Constructor
- Parameters
key (str) – the key that rule is to apply to.
name (str) – the name of the field that value was assigned
value (object) – the value that is assigned to
field_nameraise_errors (bool) – determinins if rule could raise an error when validation fails
originator (object) – the object that attributes validated for
- Raises
TypeError – If any arg is not of the correct type
- validate() bool[source]
Valids
- Raises
ValueError – If
raise_errorsisFalseand value is less then0or greater than255.- Returns
Trueif Validation passes; Otherwise,False.- Return type
bool
- property field_name: str
Name of the field assigned.
- Getter
Gets the name of the field assigned
- Setter
Sets the name of the field assigned
- property field_value: object
The value assigned to
field_name- Getter
Gets value assigned to
field_name- Setter
Sets value assigned to
field_name
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes validated for
- property raise_errors: bool
Determines if a rule can raise an error when validation fails.
- Getter
Gets if a rule could raise an error when validation fails
- Setter
Sets if a rule could raise an error when validation fails
RuleFloat Class
- class kwhelp.rules.RuleFloat(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Bases:
kwhelp.rules.IRuleRule that matched only if value is to type
float.- __init__(key: str, name: str, value: object, raise_errors: bool, originator: object)
Constructor
- Parameters
key (str) – the key that rule is to apply to.
name (str) – the name of the field that value was assigned
value (object) – the value that is assigned to
field_nameraise_errors (bool) – determinins if rule could raise an error when validation fails
originator (object) – the object that attributes validated for
- Raises
TypeError – If any arg is not of the correct type
- validate() bool[source]
Validates that value to assign is a float
- Raises
TypeError – If
raise_errorsisTrueandfield_valueis not a float.- Returns
Trueiffield_valueis a positive float; Otherwise,False.- Return type
bool
- property field_name: str
Name of the field assigned.
- Getter
Gets the name of the field assigned
- Setter
Sets the name of the field assigned
- property field_value: object
The value assigned to
field_name- Getter
Gets value assigned to
field_name- Setter
Sets value assigned to
field_name
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes validated for
- property raise_errors: bool
Determines if a rule can raise an error when validation fails.
- Getter
Gets if a rule could raise an error when validation fails
- Setter
Sets if a rule could raise an error when validation fails
RuleFloatNegative Class
- class kwhelp.rules.RuleFloatNegative(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Bases:
kwhelp.rules.RuleFloatRule that matched only if value is less than
0.0.- __init__(key: str, name: str, value: object, raise_errors: bool, originator: object)
Constructor
- Parameters
key (str) – the key that rule is to apply to.
name (str) – the name of the field that value was assigned
value (object) – the value that is assigned to
field_nameraise_errors (bool) – determinins if rule could raise an error when validation fails
originator (object) – the object that attributes validated for
- Raises
TypeError – If any arg is not of the correct type
- validate() bool[source]
Validates that value to assign is a negative float
- Raises
ValueError – If
raise_errorsisTrueandfield_valueis not a negative float.- Returns
Trueiffield_valueis a negative float; Otherwise,False.- Return type
bool
- property field_name: str
Name of the field assigned.
- Getter
Gets the name of the field assigned
- Setter
Sets the name of the field assigned
- property field_value: object
The value assigned to
field_name- Getter
Gets value assigned to
field_name- Setter
Sets value assigned to
field_name
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes validated for
- property raise_errors: bool
Determines if a rule can raise an error when validation fails.
- Getter
Gets if a rule could raise an error when validation fails
- Setter
Sets if a rule could raise an error when validation fails
RuleFloatNegativeOrZero Class
- class kwhelp.rules.RuleFloatNegativeOrZero(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Bases:
kwhelp.rules.RuleFloatRule that matched only if value is equal or less than
0.0.- __init__(key: str, name: str, value: object, raise_errors: bool, originator: object)
Constructor
- Parameters
key (str) – the key that rule is to apply to.
name (str) – the name of the field that value was assigned
value (object) – the value that is assigned to
field_nameraise_errors (bool) – determinins if rule could raise an error when validation fails
originator (object) – the object that attributes validated for
- Raises
TypeError – If any arg is not of the correct type
- validate() bool[source]
Validates that value to assign is equal to
0.0or a negative float- Raises
ValueError – If
raise_errorsisTrueandfield_valueis not a negative float.- Returns
Trueiffield_valueis equal to0.0or a negative float; Otherwise,False.- Return type
bool
- property field_name: str
Name of the field assigned.
- Getter
Gets the name of the field assigned
- Setter
Sets the name of the field assigned
- property field_value: object
The value assigned to
field_name- Getter
Gets value assigned to
field_name- Setter
Sets value assigned to
field_name
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes validated for
- property raise_errors: bool
Determines if a rule can raise an error when validation fails.
- Getter
Gets if a rule could raise an error when validation fails
- Setter
Sets if a rule could raise an error when validation fails
RuleFloatPositive Class
- class kwhelp.rules.RuleFloatPositive(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Bases:
kwhelp.rules.RuleFloatRule that matched only if value is equal or greater than
0.0.- __init__(key: str, name: str, value: object, raise_errors: bool, originator: object)
Constructor
- Parameters
key (str) – the key that rule is to apply to.
name (str) – the name of the field that value was assigned
value (object) – the value that is assigned to
field_nameraise_errors (bool) – determinins if rule could raise an error when validation fails
originator (object) – the object that attributes validated for
- Raises
TypeError – If any arg is not of the correct type
- validate() bool[source]
Validates that value to assign is a positive float
- Raises
ValueError – If
raise_errorsisTrueandfield_valueis not a positive float.- Returns
Trueiffield_valueis a positive float; Otherwise,False.- Return type
bool
- property field_name: str
Name of the field assigned.
- Getter
Gets the name of the field assigned
- Setter
Sets the name of the field assigned
- property field_value: object
The value assigned to
field_name- Getter
Gets value assigned to
field_name- Setter
Sets value assigned to
field_name
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes validated for
- property raise_errors: bool
Determines if a rule can raise an error when validation fails.
- Getter
Gets if a rule could raise an error when validation fails
- Setter
Sets if a rule could raise an error when validation fails
RuleFloatZero Class
- class kwhelp.rules.RuleFloatZero(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Bases:
kwhelp.rules.RuleFloatRule that matched only if value is equal to
0.0.- __init__(key: str, name: str, value: object, raise_errors: bool, originator: object)
Constructor
- Parameters
key (str) – the key that rule is to apply to.
name (str) – the name of the field that value was assigned
value (object) – the value that is assigned to
field_nameraise_errors (bool) – determinins if rule could raise an error when validation fails
originator (object) – the object that attributes validated for
- Raises
TypeError – If any arg is not of the correct type
- validate() bool[source]
Validates that value to assign equals
0.0float- Raises
ValueError – If
raise_errorsisTrueandfield_valueis not equal to0.0float.- Returns
Trueiffield_valueequals0.0float; Otherwise,False.- Return type
bool
- property field_name: str
Name of the field assigned.
- Getter
Gets the name of the field assigned
- Setter
Sets the name of the field assigned
- property field_value: object
The value assigned to
field_name- Getter
Gets value assigned to
field_name- Setter
Sets value assigned to
field_name
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes validated for
- property raise_errors: bool
Determines if a rule can raise an error when validation fails.
- Getter
Gets if a rule could raise an error when validation fails
- Setter
Sets if a rule could raise an error when validation fails
RuleInt Class
- class kwhelp.rules.RuleInt(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Bases:
kwhelp.rules.IRuleRule that matched only if value is instance of
int.Note
If value is a of type
boolthen validation will fail for this rule.- __init__(key: str, name: str, value: object, raise_errors: bool, originator: object)
Constructor
- Parameters
key (str) – the key that rule is to apply to.
name (str) – the name of the field that value was assigned
value (object) – the value that is assigned to
field_nameraise_errors (bool) – determinins if rule could raise an error when validation fails
originator (object) – the object that attributes validated for
- Raises
TypeError – If any arg is not of the correct type
- validate() bool[source]
Validates that value to assign is an int
- Raises
TypeError – If
raise_errorsisTrueandfield_valueis not an int.- Returns
Trueiffield_valueis anint; Otherwise,False.- Return type
bool
- property field_name: str
Name of the field assigned.
- Getter
Gets the name of the field assigned
- Setter
Sets the name of the field assigned
- property field_value: object
The value assigned to
field_name- Getter
Gets value assigned to
field_name- Setter
Sets value assigned to
field_name
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes validated for
- property raise_errors: bool
Determines if a rule can raise an error when validation fails.
- Getter
Gets if a rule could raise an error when validation fails
- Setter
Sets if a rule could raise an error when validation fails
RuleIntNegative Class
- class kwhelp.rules.RuleIntNegative(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Bases:
kwhelp.rules.RuleIntRule that matched only if value is less than
0.- __init__(key: str, name: str, value: object, raise_errors: bool, originator: object)
Constructor
- Parameters
key (str) – the key that rule is to apply to.
name (str) – the name of the field that value was assigned
value (object) – the value that is assigned to
field_nameraise_errors (bool) – determinins if rule could raise an error when validation fails
originator (object) – the object that attributes validated for
- Raises
TypeError – If any arg is not of the correct type
- validate() bool[source]
Validates that value to assign is a negative int
- Raises
TypeError – If
raise_errorsisTrueandfield_valueis not a negative int.- Returns
Trueiffield_valueis a negative int; Otherwise,False.- Return type
bool
- property field_name: str
Name of the field assigned.
- Getter
Gets the name of the field assigned
- Setter
Sets the name of the field assigned
- property field_value: object
The value assigned to
field_name- Getter
Gets value assigned to
field_name- Setter
Sets value assigned to
field_name
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes validated for
- property raise_errors: bool
Determines if a rule can raise an error when validation fails.
- Getter
Gets if a rule could raise an error when validation fails
- Setter
Sets if a rule could raise an error when validation fails
RuleIntNegativeOrZero Class
- class kwhelp.rules.RuleIntNegativeOrZero(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Bases:
kwhelp.rules.RuleIntRule that matched only if value is equal or less than
0.- __init__(key: str, name: str, value: object, raise_errors: bool, originator: object)
Constructor
- Parameters
key (str) – the key that rule is to apply to.
name (str) – the name of the field that value was assigned
value (object) – the value that is assigned to
field_nameraise_errors (bool) – determinins if rule could raise an error when validation fails
originator (object) – the object that attributes validated for
- Raises
TypeError – If any arg is not of the correct type
- validate() bool[source]
Validates that value to assign is equal to zero or a negative int
- Raises
TypeError – If
raise_errorsisTrueandfield_valueis not a negative int.- Returns
Trueiffield_valueis equal to zero or a negative int; Otherwise,False.- Return type
bool
- property field_name: str
Name of the field assigned.
- Getter
Gets the name of the field assigned
- Setter
Sets the name of the field assigned
- property field_value: object
The value assigned to
field_name- Getter
Gets value assigned to
field_name- Setter
Sets value assigned to
field_name
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes validated for
- property raise_errors: bool
Determines if a rule can raise an error when validation fails.
- Getter
Gets if a rule could raise an error when validation fails
- Setter
Sets if a rule could raise an error when validation fails
RuleIntPositive Class
- class kwhelp.rules.RuleIntPositive(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Bases:
kwhelp.rules.RuleIntRule that matched only if value is equal or greater than
0.- __init__(key: str, name: str, value: object, raise_errors: bool, originator: object)
Constructor
- Parameters
key (str) – the key that rule is to apply to.
name (str) – the name of the field that value was assigned
value (object) – the value that is assigned to
field_nameraise_errors (bool) – determinins if rule could raise an error when validation fails
originator (object) – the object that attributes validated for
- Raises
TypeError – If any arg is not of the correct type
- validate() bool[source]
Validates that value to assign is a posivite int
- Raises
TypeError – If
raise_errorsisTrueandfield_valueis not a positive int.- Returns
Trueiffield_valueis a positive int; Otherwise,False.- Return type
bool
- property field_name: str
Name of the field assigned.
- Getter
Gets the name of the field assigned
- Setter
Sets the name of the field assigned
- property field_value: object
The value assigned to
field_name- Getter
Gets value assigned to
field_name- Setter
Sets value assigned to
field_name
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes validated for
- property raise_errors: bool
Determines if a rule can raise an error when validation fails.
- Getter
Gets if a rule could raise an error when validation fails
- Setter
Sets if a rule could raise an error when validation fails
RuleIntZero Class
- class kwhelp.rules.RuleIntZero(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Bases:
kwhelp.rules.RuleIntRule that matched only if value is equal to
0.- __init__(key: str, name: str, value: object, raise_errors: bool, originator: object)
Constructor
- Parameters
key (str) – the key that rule is to apply to.
name (str) – the name of the field that value was assigned
value (object) – the value that is assigned to
field_nameraise_errors (bool) – determinins if rule could raise an error when validation fails
originator (object) – the object that attributes validated for
- Raises
TypeError – If any arg is not of the correct type
- validate() bool[source]
Validates that value to assign is equal to
0int.- Raises
ValueError – If
raise_errorsisTrueandfield_valueis not equal to0int.- Returns
Trueiffield_valueequals0int; Otherwise,False.- Return type
bool
- property field_name: str
Name of the field assigned.
- Getter
Gets the name of the field assigned
- Setter
Sets the name of the field assigned
- property field_value: object
The value assigned to
field_name- Getter
Gets value assigned to
field_name- Setter
Sets value assigned to
field_name
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes validated for
- property raise_errors: bool
Determines if a rule can raise an error when validation fails.
- Getter
Gets if a rule could raise an error when validation fails
- Setter
Sets if a rule could raise an error when validation fails
RuleIterable Class
- class kwhelp.rules.RuleIterable(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Bases:
kwhelp.rules.IRuleRule that matched only if value is iterable such as list, tuple, set.
- __init__(key: str, name: str, value: object, raise_errors: bool, originator: object)
Constructor
- Parameters
key (str) – the key that rule is to apply to.
name (str) – the name of the field that value was assigned
value (object) – the value that is assigned to
field_nameraise_errors (bool) – determinins if rule could raise an error when validation fails
originator (object) – the object that attributes validated for
- Raises
TypeError – If any arg is not of the correct type
- validate() bool[source]
Validates that value to assign is iterable
- Raises
TypeError – If
raise_errorsisTrueandfield_valueis not iterable.- Returns
Trueiffield_valueis a iterable; Otherwise,False.- Return type
bool
- property field_name: str
Name of the field assigned.
- Getter
Gets the name of the field assigned
- Setter
Sets the name of the field assigned
- property field_value: object
The value assigned to
field_name- Getter
Gets value assigned to
field_name- Setter
Sets value assigned to
field_name
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes validated for
- property raise_errors: bool
Determines if a rule can raise an error when validation fails.
- Getter
Gets if a rule could raise an error when validation fails
- Setter
Sets if a rule could raise an error when validation fails
RuleNone Class
- class kwhelp.rules.RuleNone(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Bases:
kwhelp.rules.IRuleRule that matched only if value is
None.- __init__(key: str, name: str, value: object, raise_errors: bool, originator: object)
Constructor
- Parameters
key (str) – the key that rule is to apply to.
name (str) – the name of the field that value was assigned
value (object) – the value that is assigned to
field_nameraise_errors (bool) – determinins if rule could raise an error when validation fails
originator (object) – the object that attributes validated for
- Raises
TypeError – If any arg is not of the correct type
- validate() bool[source]
Validates that value to assign to attribute is
None.- Raises
ValueError – If
raise_errorsisTrueandfield_valueis notNone.- Returns
Trueiffield_valueisNone; Otherwise,False.- Return type
bool
- property field_name: str
Name of the field assigned.
- Getter
Gets the name of the field assigned
- Setter
Sets the name of the field assigned
- property field_value: object
The value assigned to
field_name- Getter
Gets value assigned to
field_name- Setter
Sets value assigned to
field_name
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes validated for
- property raise_errors: bool
Determines if a rule can raise an error when validation fails.
- Getter
Gets if a rule could raise an error when validation fails
- Setter
Sets if a rule could raise an error when validation fails
RuleNotIterable Class
- class kwhelp.rules.RuleNotIterable(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Bases:
kwhelp.rules.IRuleRule that matched only if value is not iterable.
- __init__(key: str, name: str, value: object, raise_errors: bool, originator: object)
Constructor
- Parameters
key (str) – the key that rule is to apply to.
name (str) – the name of the field that value was assigned
value (object) – the value that is assigned to
field_nameraise_errors (bool) – determinins if rule could raise an error when validation fails
originator (object) – the object that attributes validated for
- Raises
TypeError – If any arg is not of the correct type
- validate() bool[source]
Validates that value to assign is not iterable
- Raises
TypeError – If
raise_errorsisTrueandfield_valueis iterable.- Returns
Trueiffield_valueis a not iterable; Otherwise,False.- Return type
bool
- property field_name: str
Name of the field assigned.
- Getter
Gets the name of the field assigned
- Setter
Sets the name of the field assigned
- property field_value: object
The value assigned to
field_name- Getter
Gets value assigned to
field_name- Setter
Sets value assigned to
field_name
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes validated for
- property raise_errors: bool
Determines if a rule can raise an error when validation fails.
- Getter
Gets if a rule could raise an error when validation fails
- Setter
Sets if a rule could raise an error when validation fails
RuleNotNone Class
- class kwhelp.rules.RuleNotNone(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Bases:
kwhelp.rules.IRuleRule that matched only if value is not
None.- __init__(key: str, name: str, value: object, raise_errors: bool, originator: object)
Constructor
- Parameters
key (str) – the key that rule is to apply to.
name (str) – the name of the field that value was assigned
value (object) – the value that is assigned to
field_nameraise_errors (bool) – determinins if rule could raise an error when validation fails
originator (object) – the object that attributes validated for
- Raises
TypeError – If any arg is not of the correct type
- validate() bool[source]
Validates that value to assign to attribute is not
None.- Raises
ValueError – If
raise_errorsisTrueandfield_valueisNone.- Returns
Trueiffield_valueis notNone; Otherwise,False.- Return type
bool
- property field_name: str
Name of the field assigned.
- Getter
Gets the name of the field assigned
- Setter
Sets the name of the field assigned
- property field_value: object
The value assigned to
field_name- Getter
Gets value assigned to
field_name- Setter
Sets value assigned to
field_name
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes validated for
- property raise_errors: bool
Determines if a rule can raise an error when validation fails.
- Getter
Gets if a rule could raise an error when validation fails
- Setter
Sets if a rule could raise an error when validation fails
RuleNumber Class
- class kwhelp.rules.RuleNumber(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Bases:
kwhelp.rules.IRuleRule that matched only if value is a valid number.
Note
If value is a of type
boolthen validation will fail for this rule.- __init__(key: str, name: str, value: object, raise_errors: bool, originator: object)
Constructor
- Parameters
key (str) – the key that rule is to apply to.
name (str) – the name of the field that value was assigned
value (object) – the value that is assigned to
field_nameraise_errors (bool) – determinins if rule could raise an error when validation fails
originator (object) – the object that attributes validated for
- Raises
TypeError – If any arg is not of the correct type
- validate() bool[source]
Validates that value to assign is a number
- Raises
TypeError – If
raise_errorsisTrueandfield_valueis not a number.- Returns
Trueiffield_valueis a number; Otherwise,False.- Return type
bool
- property field_name: str
Name of the field assigned.
- Getter
Gets the name of the field assigned
- Setter
Sets the name of the field assigned
- property field_value: object
The value assigned to
field_name- Getter
Gets value assigned to
field_name- Setter
Sets value assigned to
field_name
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes validated for
- property raise_errors: bool
Determines if a rule can raise an error when validation fails.
- Getter
Gets if a rule could raise an error when validation fails
- Setter
Sets if a rule could raise an error when validation fails
RulePath Class
- class kwhelp.rules.RulePath(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Bases:
kwhelp.rules.IRuleRule that matched only if value is instance of
Path.- __init__(key: str, name: str, value: object, raise_errors: bool, originator: object)
Constructor
- Parameters
key (str) – the key that rule is to apply to.
name (str) – the name of the field that value was assigned
value (object) – the value that is assigned to
field_nameraise_errors (bool) – determinins if rule could raise an error when validation fails
originator (object) – the object that attributes validated for
- Raises
TypeError – If any arg is not of the correct type
- validate() bool[source]
Validates that value to assign is a Path
- Raises
TypeError – If
raise_errorsisTrueandfield_valueis not instance of Path.- Returns
Trueiffield_valueis a bool; Otherwise,False.- Return type
bool
- property field_name: str
Name of the field assigned.
- Getter
Gets the name of the field assigned
- Setter
Sets the name of the field assigned
- property field_value: object
The value assigned to
field_name- Getter
Gets value assigned to
field_name- Setter
Sets value assigned to
field_name
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes validated for
- property raise_errors: bool
Determines if a rule can raise an error when validation fails.
- Getter
Gets if a rule could raise an error when validation fails
- Setter
Sets if a rule could raise an error when validation fails
RulePathExist Class
- class kwhelp.rules.RulePathExist(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Bases:
kwhelp.rules.RulePathRule that matched only if value is instance of
Pathand path exist.- __init__(key: str, name: str, value: object, raise_errors: bool, originator: object)
Constructor
- Parameters
key (str) – the key that rule is to apply to.
name (str) – the name of the field that value was assigned
value (object) – the value that is assigned to
field_nameraise_errors (bool) – determinins if rule could raise an error when validation fails
originator (object) – the object that attributes validated for
- Raises
TypeError – If any arg is not of the correct type
- validate() bool[source]
Validates that value to assign is a path that exist
- Raises
FileNotFoundError – If
raise_errorsisTrueandfield_valueis path does not exist.- Returns
Trueiffield_valueis an existing path; Otherwise,False.- Return type
bool
- property field_name: str
Name of the field assigned.
- Getter
Gets the name of the field assigned
- Setter
Sets the name of the field assigned
- property field_value: object
The value assigned to
field_name- Getter
Gets value assigned to
field_name- Setter
Sets value assigned to
field_name
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes validated for
- property raise_errors: bool
Determines if a rule can raise an error when validation fails.
- Getter
Gets if a rule could raise an error when validation fails
- Setter
Sets if a rule could raise an error when validation fails
RulePathNotExist Class
- class kwhelp.rules.RulePathNotExist(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Bases:
kwhelp.rules.RulePathRule that matched only if value is instance of
Pathand path does not exist.- __init__(key: str, name: str, value: object, raise_errors: bool, originator: object)
Constructor
- Parameters
key (str) – the key that rule is to apply to.
name (str) – the name of the field that value was assigned
value (object) – the value that is assigned to
field_nameraise_errors (bool) – determinins if rule could raise an error when validation fails
originator (object) – the object that attributes validated for
- Raises
TypeError – If any arg is not of the correct type
- validate() bool[source]
Validates that value to assign is a Path that does not exist
- Raises
FileExistsError – If
raise_errorsisTrueandfield_valueis path that is existing.- Returns
Trueiffield_valueis a p ath that does not exist; Otherwise,False.- Return type
bool
- property field_name: str
Name of the field assigned.
- Getter
Gets the name of the field assigned
- Setter
Sets the name of the field assigned
- property field_value: object
The value assigned to
field_name- Getter
Gets value assigned to
field_name- Setter
Sets value assigned to
field_name
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes validated for
- property raise_errors: bool
Determines if a rule can raise an error when validation fails.
- Getter
Gets if a rule could raise an error when validation fails
- Setter
Sets if a rule could raise an error when validation fails
RuleStr Class
- class kwhelp.rules.RuleStr(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Bases:
kwhelp.rules.IRuleRule that matched only if value is of type
str.- __init__(key: str, name: str, value: object, raise_errors: bool, originator: object)
Constructor
- Parameters
key (str) – the key that rule is to apply to.
name (str) – the name of the field that value was assigned
value (object) – the value that is assigned to
field_nameraise_errors (bool) – determinins if rule could raise an error when validation fails
originator (object) – the object that attributes validated for
- Raises
TypeError – If any arg is not of the correct type
- validate() bool[source]
Validates that value to assign is a string
- Raises
TypeError – If
raise_errorsisTrueandfield_valueis not instance of string.- Returns
Trueiffield_valueis a string; Otherwise,False.- Return type
bool
- property field_name: str
Name of the field assigned.
- Getter
Gets the name of the field assigned
- Setter
Sets the name of the field assigned
- property field_value: object
The value assigned to
field_name- Getter
Gets value assigned to
field_name- Setter
Sets value assigned to
field_name
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes validated for
- property raise_errors: bool
Determines if a rule can raise an error when validation fails.
- Getter
Gets if a rule could raise an error when validation fails
- Setter
Sets if a rule could raise an error when validation fails
RuleStrEmpty Class
- class kwhelp.rules.RuleStrEmpty(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Bases:
kwhelp.rules.RuleStrRule that matched only if value is equal to empty string.
- __init__(key: str, name: str, value: object, raise_errors: bool, originator: object)
Constructor
- Parameters
key (str) – the key that rule is to apply to.
name (str) – the name of the field that value was assigned
value (object) – the value that is assigned to
field_nameraise_errors (bool) – determinins if rule could raise an error when validation fails
originator (object) – the object that attributes validated for
- Raises
TypeError – If any arg is not of the correct type
- validate() bool[source]
Validates that value to assign is a string and is an empty string.
- Raises
ValueError – If
raise_errorsisTrueandfield_valueis not an empty string.- Returns
Trueif value is an empty string; Otherwise;False.- Return type
bool
- property field_name: str
Name of the field assigned.
- Getter
Gets the name of the field assigned
- Setter
Sets the name of the field assigned
- property field_value: object
The value assigned to
field_name- Getter
Gets value assigned to
field_name- Setter
Sets value assigned to
field_name
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes validated for
- property raise_errors: bool
Determines if a rule can raise an error when validation fails.
- Getter
Gets if a rule could raise an error when validation fails
- Setter
Sets if a rule could raise an error when validation fails
RuleStrNotNullEmptyWs Class
- class kwhelp.rules.RuleStrNotNullEmptyWs(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Bases:
kwhelp.rules.RuleStrNotNullOrEmptyRule that matched only if value is not
None, empty or whitespace.- __init__(key: str, name: str, value: object, raise_errors: bool, originator: object)
Constructor
- Parameters
key (str) – the key that rule is to apply to.
name (str) – the name of the field that value was assigned
value (object) – the value that is assigned to
field_nameraise_errors (bool) – determinins if rule could raise an error when validation fails
originator (object) – the object that attributes validated for
- Raises
TypeError – If any arg is not of the correct type
- validate() bool[source]
Validates that value to assign is a string and is not a empty or whitespace string.
- Raises
ValueError – If
raise_errorsisTrueandfield_valueis not instance of string or is empty or whitespace string- Returns
Trueif value is valid; Otherwise;False.- Return type
bool
- property field_name: str
Name of the field assigned.
- Getter
Gets the name of the field assigned
- Setter
Sets the name of the field assigned
- property field_value: object
The value assigned to
field_name- Getter
Gets value assigned to
field_name- Setter
Sets value assigned to
field_name
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes validated for
- property raise_errors: bool
Determines if a rule can raise an error when validation fails.
- Getter
Gets if a rule could raise an error when validation fails
- Setter
Sets if a rule could raise an error when validation fails
RuleStrNotNullOrEmpty Class
- class kwhelp.rules.RuleStrNotNullOrEmpty(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Bases:
kwhelp.rules.RuleStrRule that matched only if value is not
Noneor empty string.- __init__(key: str, name: str, value: object, raise_errors: bool, originator: object)
Constructor
- Parameters
key (str) – the key that rule is to apply to.
name (str) – the name of the field that value was assigned
value (object) – the value that is assigned to
field_nameraise_errors (bool) – determinins if rule could raise an error when validation fails
originator (object) – the object that attributes validated for
- Raises
TypeError – If any arg is not of the correct type
- validate() bool[source]
Validates that value to assign is a string and is not a empty string.
- Raises
ValueError – If
raise_errorsisTrueandfield_valueis not instance of string or is empty string- Returns
Trueif value is valid; Otherwise;False.- Return type
bool
- property field_name: str
Name of the field assigned.
- Getter
Gets the name of the field assigned
- Setter
Sets the name of the field assigned
- property field_value: object
The value assigned to
field_name- Getter
Gets value assigned to
field_name- Setter
Sets value assigned to
field_name
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes validated for
- property raise_errors: bool
Determines if a rule can raise an error when validation fails.
- Getter
Gets if a rule could raise an error when validation fails
- Setter
Sets if a rule could raise an error when validation fails
RuleStrPathExist Class
- class kwhelp.rules.RuleStrPathExist(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Bases:
kwhelp.rules.RuleStrRule that matched only if value is instance of str and path exist.
- __init__(key: str, name: str, value: object, raise_errors: bool, originator: object)
Constructor
- Parameters
key (str) – the key that rule is to apply to.
name (str) – the name of the field that value was assigned
value (object) – the value that is assigned to
field_nameraise_errors (bool) – determinins if rule could raise an error when validation fails
originator (object) – the object that attributes validated for
- Raises
TypeError – If any arg is not of the correct type
- validate() bool[source]
Validates that value to assign is a str path that exist
- Raises
FileNotFoundError – If
raise_errorsisTrueandfield_valueis path does not exist.- Returns
Trueiffield_valueis a path that does exist; Otherwise,False.- Return type
bool
- property field_name: str
Name of the field assigned.
- Getter
Gets the name of the field assigned
- Setter
Sets the name of the field assigned
- property field_value: object
The value assigned to
field_name- Getter
Gets value assigned to
field_name- Setter
Sets value assigned to
field_name
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes validated for
- property raise_errors: bool
Determines if a rule can raise an error when validation fails.
- Getter
Gets if a rule could raise an error when validation fails
- Setter
Sets if a rule could raise an error when validation fails
RuleStrPathNotExist Class
- class kwhelp.rules.RuleStrPathNotExist(key: str, name: str, value: object, raise_errors: bool, originator: object)[source]
Bases:
kwhelp.rules.RuleStrRule that matched only if value is instance of str and path is not existing.
- __init__(key: str, name: str, value: object, raise_errors: bool, originator: object)
Constructor
- Parameters
key (str) – the key that rule is to apply to.
name (str) – the name of the field that value was assigned
value (object) – the value that is assigned to
field_nameraise_errors (bool) – determinins if rule could raise an error when validation fails
originator (object) – the object that attributes validated for
- Raises
TypeError – If any arg is not of the correct type
- validate() bool[source]
Validates that value to assign is a path not existing
- Raises
FileExistsError – If
raise_errorsisTrueandfield_valueis a path that is not existing.- Returns
Trueiffield_valueis a path that does not exist; Otherwise,False.- Return type
bool
- property field_name: str
Name of the field assigned.
- Getter
Gets the name of the field assigned
- Setter
Sets the name of the field assigned
- property field_value: object
The value assigned to
field_name- Getter
Gets value assigned to
field_name- Setter
Sets value assigned to
field_name
- property key: str
Gets the key currently being read
- property originator: object
Gets object that attributes validated for
- property raise_errors: bool
Determines if a rule can raise an error when validation fails.
- Getter
Gets if a rule could raise an error when validation fails
- Setter
Sets if a rule could raise an error when validation fails
exceptions
CancelEventError Class
ReservedAttributeError Class
RuleError Class
- class kwhelp.exceptions.RuleError(**kwargs)[source]
Rule Error
- __init__(**kwargs)[source]
Constructor
- Keyword Arguments
err_rule (Type[IRule], optional) – Rule that caused exception.
rules_all (Iterable[Type[IRule]], optional) – List of rules that were to all be matched. One of these rules is usually the reason this exception is being raised.
rules_any (Iterable[Type[IRule]], optional) – List of rules that required one or more matches. One of these rules is usually the reason this exception is being raised.
arg_name (str, optional) – Name of the argument for this exception.
errors (Union[Exception, Iterable[Exception]], optional) – Exception or Exceptions that cause this error.
fn_name (str, optional) – Name of function/property that raise error.
msg (str, optional) – Optional message to append.
- static from_rule_error(rule_error: kwhelp.exceptions.RuleError, **kwargs) kwhelp.exceptions.RuleError[source]
Creates a new RuleError from an existing RuleError
- property arg_name: Optional[str]
Gets Name of the argument for this exception
- property err_rule: Optional[Type[kwhelp.rules.IRule]]
Gets rule that caused exception.
- property errors: Optional[Union[Exception, Iterable[Exception]]]
Gets Exception or Exceptions that cause this error
- property fn_name: Union[None, str]
Gets the function/property name that raised the error
- property msg: Optional[str]
Gets any messsage that is appended
- property rules_all: List[Type[kwhelp.rules.IRule]]
Gets list of rules that were to all be matched.
- property rules_any: List[Type[kwhelp.rules.IRule]]
Gets of rules that required one or more matches.