Memorization Decorator

fib_memory.py

## Generic memorization wrapper
def memorize(fn):
    data = {}
    def _wrapped_memorize(*args):
        key = hash(args)
        if key in data:
            return data[key]
        val = fn(*args)
        data[key] = val
        return val

    return _wrapped_memorize

@memorize
def fib(n):
    if n < 0:
        raise Exception("Bad Input")
    if n == 0 or n == 1:
        return n
    return fib(n - 1) + fib(n - 2)

print fib(100)