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

All Rules

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

Any Rules

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