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:

  • int is an index of an item in rules

  • IRule a 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.

Example Usage

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

Included Rules