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