缓存 装饰器

def memoize(fn):
    stored_results = {}
　　@functools.wrap(fn)
    def memoized(*args):
        try:
            # try to get the cached result
            return stored_results[args]
        except KeyError:
            # nothing was cached for those args. let's fix that.
            result = stored_results[args] = fn(*args)
            return result

    return memoized

使用：

def fib(n):
    return n if n in [0, 1] else fib(n - 2) + fib(n - 1)
fib = memoize(fib)

or

@memoize
def fib(n):
    return n if n in [0, 1] else fib(n - 2) + fib(n - 1)