Fixing Python wtf -- parameter defaults

fix_params.py

import functools
import inspect
 
def fix_params(func):
    @functools.wraps(func)
    def wrapper(*args, **kwargs):
        original_defaults = func.__defaults__
        new_defaults = []
        for val in func.__defaults__:
            if val == []:
                new_defaults.append([])
            elif val == {}:
                new_defaults.append({})
            elif callable(val):
                sig = inspect.signature(val)
                if sig.parameters == {}:
                    new_defaults.append(val())
                else:
                    new_defaults.append(val)
            else:
                new_defaults.append(val)
 
        func.__defaults__ = tuple(new_defaults)
 
        rval = func(*args, **kwargs)
        func.__defaults__ = original_defaults
        return rval
 

    return wrapper

VAL = 0
import datetime
@fix_params
def do_something(a, b, inputs=[], my_opts={}, my_f = lambda: datetime.datetime.now()):
    global VAL
    VAL += 1
    inputs.append(1)
    my_opts[VAL] = VAL
    print(inputs)
    print(my_opts)
    print(my_f)
    return inputs
 
 
def main():
    do_something(0, 0) 
    do_something(1,1) 
 
if __name__ == "__main__":
    main()