Memoization in Python

memoization.py

#!/usr/bin/env python
# -*- encoding:utf-8 -*-

"""
Solution to Project Euler Problem
http://projecteuler.net/

by Apalala <[email protected]>
(cc) Attribution-ShareAlike 
http://creativecommons.org/licenses/by-sa/3.0/

Memoization.
"""
import functools

def memoize(func):
    func.cache = {}
    def memoize(*args, **kw):
        if kw: # frozenset is used to ensure hashability
            key = args, frozenset(kw.iteritems())
        else:
            key = args
        cache = func.cache
        if key in cache:
            return cache[key]
        else:
            cache[key] = result = func(*args, **kw)
            return result
    return functools.update_wrapper(memoize, func)

if __name__ == '__main__':
    pass