2008.09.19 15:48 python decorator to make function or method cachable

For one project I just needed to make a decorator which turns any Python function or method into cachable version. I mean, if the function is called several times with the same arguments, the result is being take from cache. Finally I managed to do it. Here it is:
class cachable_function(object):
	do = None
	cache = None
	def __init__(self, do):
		self.do = do
		self.cache = {}
	def arguments2index(self, arguments, named_arguments):
		index = ()
		for key in named_arguments:
			index += (key, named_arguments[key]),
		index = (arguments, index)
		return index
	def __call__(self, *arguments, **named_arguments):
		index = self.arguments2index(arguments, named_arguments)
		try:
			result = self.cache[index]
		except KeyError:
			result = self.do(*arguments, **named_arguments)
			self.cache[index] = result
		return result

class cachable_method(cachable_function):
	def __get__(cachable_method_self, method_s_object_self, type=None):
		def cachable_method(*arguments, **named_arguments):
			result = cachable_method_self.__call__(method_s_object_self, *arguments, **named_arguments)
			return result
		return cachable_method

if __name__ == \'__main__\':
	class klasa:
		@cachable_method
		def f1(self, a, b):
			return a/b
	k = klasa()
	print k.f1(10, 2)
	print k.f1(10, 5)
	print k.f1(10, 2)
	print k.f1(10, 5)
	print k.f1(b=2, a=10)
	print k.f1(b=2, a=10)

I haven\'t tested it well yet, but it seems to work.

komentarze:

ksywa:

tu wpisz cyfrę cztery: (to takie zabezpieczenie antyspamowe)

komentarze wulgarne albo co mi się nie spodobają będę kasował


powrot na strone glowna

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