#!/usr/bin/env python3

from datetime import datetime
import functools


def invocation_logged(func):
    @functools.wraps(func)
    def wrapper(*args, **kwargs):
        now = datetime.now()
        timestamp = now.strftime("%d-%b-%Y (%H:%M:%S.%f)")
        print("%s(%s): Entered function" % (func.__name__, timestamp))
        ret = func(*args, **kwargs)
        now = datetime.now()
        timestamp = now.strftime("%d-%b-%Y (%H:%M:%S.%f)")
        print("%s(%s): Exited function" % (func.__name__, timestamp))
        return ret

    return wrapper


# Test
# @invocation_logged
# def f(x):
#    print(x * x)
#    return x * x
#
# q = f(10)
# print(q)