waste_time.py

import time

def time_it(fun):
    def wrapper(*args, **kwargs):
        start = time.time()
        res = fun(*args, **kwargs)
        end = time.time()
        print(f'Function took {end-start}s')
        
        return res
    
    return wrapper


@time_it
def waste_time():
    for i in range(10000000):
        pass

    
waste_time()

# Output
Function took 0.18418407440185547s