Cached Method decorator

cached_method.py

def cached_model_method(time=600, key_uses_args=False):
    """
    Decorates django model methods
    Use it as:

      @cached_model_method(time=1200)
      def functionToCache(arguments):
        ...
    """

    #TODO review, just for playing a little!!!
    def decorator(function):
        @functools.wraps(function)
        def wrapper(*args, **kwargs):
            #args[0] should be an instance
            if len(args) > 0 and args[0].id is not None:
                key = "%s-%s-%s-%s-%s" % (args[0].__class__, function.__name__, args[0].id, args, kwargs)
                key = hashlib.sha256(key).hexdigest()
                value = cache.get(key)
                if not value:
                    value = function(*args, **kwargs)
                    cache.set(key, value, time)
                return value
            else:
                return function(*args, **kwargs)
        return wrapper
    return decorator