使用全局变量做数据缓存

cache.py

#coding: utf8

import hashlib
import pickle
import time

CACHE = {}

def is_obsolete(entry, duration):
    return time.time() - entry['time'] > duration


def compute_key(func, args, kw):
    key = pickle.dumps((func.__name__, args, kw))
    return hashlib.sha1(key).hexdigest()


def cache(duration=10):
    def _cache(func):
        def __cache(*args, **kw):
            key = compute_key(func, args, kw)
            if key in CACHE and not is_obsolete(CACHE[key], duration) and kw.get(""):
                return CACHE[key]['value']
            result = func(*args, **kw)
            CACHE[key] = {'value': result, 'time': time.time()}
            return result
        return __cache
    return _cache