Checks argument sequence and mapping to make sure it's acceptable to call a given function with them. By request.

argspecvalid.py

import types


ARGS_FLAG = 4
KWARGS_FLAG = 8

def valid(f, args, kwargs):
    
    def dummy():
        pass

    dummy_code = dummy.__code__
    real_code = f.__code__

    args_flag = real_code.co_flags & ARGS_FLAG
    kwargs_flag = real_code.co_flags & KWARGS_FLAG

    # help(types.CodeType) for details
    test_code = types.CodeType(real_code.co_argcount,
                               real_code.co_kwonlyargcount,
                               real_code.co_nlocals,
                               dummy_code.co_stacksize,
                               args_flag | kwargs_flag,
                               dummy_code.co_code,
                               dummy_code.co_consts,
                               dummy_code.co_names,
                               real_code.co_varnames,
                               "<test>", "", 0, b"", ())

    # help(types.FunctionType) for details
    test_func = types.FunctionType(test_code, {}, "test", f.__defaults__)

    try:
        test_func(*args, **kwargs)
    except TypeError:
        return False
    else:
        return True

               
def x(a, b, c): pass
def y(a, b=1, c=2): pass
def z(a=1, b=2, c=3): pass

print(valid(x, ("hello", "goodbye", "what?"), {})) # => True
print(valid(x, ("hello", "goodbye"), {})) # => False
print(valid(y, ("hello", "goodbye", "what?"), {})) # => True
print(valid(y, (), {"a": "hello", "b": "goodbye", "c": "what"})) #=> True
print(valid(y, ("hello", "goodbye"), {"c": "what?"})) #=> True