Decorator for filtering keywords from a big dict.

kwarg_filter

import functools
import inspect


def kwarg_filter():
    def decorator(fn):
        keys = inspect.getfullargspec(fn).args  # <-- This reads the signature of the function.

        @functools.wraps(fn)
        def inner(*args, **kwargs):
            new_kwargs = {k:kwargs[k] for k in keys}  # <-- This filters out unnecessary keywords.
            return fn(*args, **new_kwargs)
        return inner
    return decorator


@kwarg_filter()
def func(a, b, c, d, e, f):
    print(a, b, c, d, e, f)

@kwarg_filter()
def func2(a,c,f):
    print(a,c,f)

@kwarg_filter()
def func3(what, f):
    print(what, f)

big_dict = {'a': 10, 'b': 20, 'c': 30, 'd': 40, 'e': 50, 'f': 60, "What": False, 'ohno': True}

# We can now call `func` with excess keywords and it will filter the excess kwargs out.
func(**big_dict)
func2(**big_dict)
func3(**big_dict)