fib.py

def fib(n):
    if n == 0:
        return 0
    elif n == 1:
        return 1
    else:
        return fib(n - 1) + fib(n - 2)
        
def wrapper(func):
    cache  = {}

    def inner(n):
        if n not in cache:
            cache[n] = func(n)
        return cache[n]
    return inner