my_decorator.py

import time


def my_decorator(fn):
  """my_decorator is a custom decorator that wraps any function
  and prints on stdout the time for execution.
  """

  def wrapper_function(*args, **kwargs):
    start_time = time.time()
    # invoking the wrapped function and getting the return value.
    value = fn(*args, **kwargs)
    print("the function execution took:", time.time() - start_time, "seconds")
    # returning the value got after invoking the wrapped function
    return value

  return wrapper_function


@my_decorator
def area(l, b):
  return l * b


>>> area(3, 4)
the function execution took: 9.5367431640625e-07 seconds
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