Caching decorator for python, like functools.lru_cache in Python 3.2+ without LRU. Written for easy debugging of dynamic programming algorthms. Also includes that caches to a pickle file, but this is only useful for very timeconsuming calls like web reque

cached.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
from functools import wraps
try:
    import cPickle as pickle
except:
    import pickle

def cached(fn):
    cache = {}
    @wraps(fn)
    def usingcache(*args,**kwargs):
        try:
            key = hash((args,kwargs))
        except TypeError:
            key = repr((args,kwargs))
        try:
            return cache[key]
        except KeyError:
            cache[key] = fn(*args,**kwargs)
            
            return cache[key]
    return usingcache

def diskcached(cachefile,saveafter=1):
    def cacheondisk(fn):
        try:
            with open(cachefile,'rb') as f:
                cache = pickle.load(f)
        except:
            cache = {}
        unsaved = [0]
        @wraps(fn)
        def usingcache(*args,**kwargs):
            try:
                key = hash((args,kwargs))
            except TypeError:
                key = repr((args,kwargs))
            try:
                ret = cache[key]
            except KeyError:
                ret = cache[key] = fn(*args,**kwargs)
                unsaved[0] += 1
                if unsaved >= saveafter:
                    with open(cachefile,'wb') as f:
                        pickle.dump(cache,f)
                    unsaved[0] = 0
            return ret
        return usingcache
    return cacheondisk

def main():
    #@diskcached('fibo',3)
    @cached
    def fib(n):
        if n in [1,2]:
            return 1
        return fib(n-1)+fib(n-2)
    print '250th fibonacci number:',fib(250)
    return 0

if __name__ == '__main__':
    main()

I suggest adding functools.wraps to the wrapper.