from werkzeug.contrib.cache import SimpleCache

CACHE_TIMEOUT = 300

cache = SimpleCache()

class cached(object):

    def __init__(self, timeout=None):
        self.timeout = timeout or CACHE_TIMEOUT

    def __call__(self, f):
        def decorator(*args, **kwargs):
            response = cache.get(request.path)
            if response is None:
                response = f(*args, **kwargs)
                cache.set(request.path, response, self.timeout)
            return response
        return decorator

@app.route("/")
@cached()
def index():
    return render_template("index.html")

类的实例可以callable，且是以func为参数的一个装饰器