PYTHON

python functools

import functools
import time

@functools.lru_cache(maxsize=256)
def find_user(name):
    # imitating slow search
    time.sleep(1)
    user = {"id": 11, "name": "Diane"}
    return user

find_user("Diane")
# kinda slow

find_user("Diane")
# blazingly fast

python functools

@cache
def factorial(n):
    return n * factorial(n-1) if n else 1

>>> factorial(10)      # no previously cached result, makes 11 recursive calls
3628800
>>> factorial(5)       # just looks up cached value result
120
>>> factorial(12)      # makes two new recursive calls, the other 10 are cached
479001600