explaining-caching.py

from functools import wraps
from time import time, sleep

def timing(f):
    """A simple timer decorator"""
    @wraps(f)
    def wrapper(*args, **kwargs):
        start = time()
        result = f(*args, **kwargs)
        end = time()
        print(f'Elapsed time {f.__name__}({args}): {end - start}')
        return result
    return wrapper


cache = {}

@timing
def func(*args) -> int:
    if args in cache:
        print("retrieve cache")
        return cache[args]
    sleep(2)
    result = sum(args)
    print("store cache")
    cache[args] = result
    return result


if __name__ == "__main__":
    print(func(1,2,3))
    print(func(1,2,3))