Decorator to print function call details - parameters names and effective values

Question

I want to make a function that being a decorator to another function will print that function call details - parameters names and effective values. My current implementation

Answer 1

Here is the updated version for Python 3.6+

import inspect


def dump_args(func):
    """
    Decorator to print function call details.

    This includes parameters names and effective values.
    """

    def wrapper(*args, **kwargs):
        func_args = inspect.signature(func).bind(*args, **kwargs).arguments
        func_args_str = ", ".join(
            "{} = {!r}".format(*item) for item in func_args.items()
        )
        print(f"{func.__module__}.{func.__qualname__} ( {func_args_str} )")
        return func(*args, **kwargs)

    return wrapper


@dump_args
def test(a, b=4, c="blah-blah", *args, **kwargs):
    pass


test(1)
test(1, 3)
test(1, d=5)
test(1, 2, 3, 4, 5, d=6, g=12.9)

---

Old version

---

Working version with default values:

def dumpArgs(func):
    '''Decorator to print function call details - parameters names and effective values'''
    def wrapper(*func_args, **func_kwargs):
        arg_names = func.func_code.co_varnames[:func.func_code.co_argcount]
        args = func_args[:len(arg_names)]
        defaults = func.func_defaults or ()
        args = args + defaults[len(defaults) - (func.func_code.co_argcount - len(args)):]
        params = zip(arg_names, args)
        args = func_args[len(arg_names):]
        if args: params.append(('args', args))
        if func_kwargs: params.append(('kwargs', func_kwargs))
        print func.func_name + ' (' + ', '.join('%s = %r' % p for p in params) + ' )'
        return func(*func_args, **func_kwargs)
    return wrapper  

@dumpArgs
def test(a, b = 4, c = 'blah-blah', *args, **kwargs):
    pass

test(1)
test(1, 3)
test(1, d = 5)
test(1, 2, 3, 4, 5, d = 6, g = 12.9)

Result:

>>> test  (  a = 1, b = 4, c = 'blah-blah' )
test  (  a = 1, b = 3, c = 'blah-blah' )
test  (  a = 1, b = 4, c = 'blah-blah', kwargs = {'d': 5} )
test  (  a = 1, b = 2, c = 3, args = (4, 5), kwargs = {'d': 6, 'g': 12.9} )