timed_cached.py

import datetime


def timed_cached(timeout=60 * 60, now=datetime.datetime.now):
	
	def outer(method_or_attribute):
		
		if not hasattr(timed_cached, '__mapping'):
			timed_cached.__mapping = {}

		if not hasattr(timed_cached, 'flush'):
			timed_cached.flush = lambda: timed_cached.__mapping.clear()
		
		def wrapped(*args, **kwargs):
			time_now = now()
			
			cache = timed_cached.__mapping.setdefault(str(method_or_attribute) + str(args) + str(kwargs), {})
			invalid = time_now > cache.get('__last_cache', time_now) + datetime.timedelta(seconds=timeout)

			if ('__cache' not in cache) or ('__last_cache' not in cache) or invalid:
				if '__cache' in cache:
					del cache['__cache']
					
				cache['__cache'] = method_or_attribute(*args, **kwargs)
				cache['__last_cache'] = time_now

			return cache['__cache']

		return wrapped

	return outer