A simple decorator to cache function calls with same arguments. Useful to optimize recursive functions with repeating calls.

cache_decorator.py

# The decorator to cache function calls
def cached(func):
    cache = dict()
    def decorator(*args):
        if tuple(args) not in cache:
            cache[tuple(args)] = func(*args)
        return cache[tuple(args)]
    return decorator

# Usage example
@cached
def fib(n):
    if n < 2:
        return n
    else:
        return fib(n-1) + fib(n-2)

print([fib(x) for x in range(1000)])