class Memoize:

"""

memoize decorator from avinash.vora

http://avinashv.net/2008/04/python-decorators-syntactic-sugar/

"""

def __init__(self, function): # runs when memoize class is called

self.function = function

self.memoized = {}

def __call__(self, *args): # runs when memoize instance is called

try:

return self.memoized[args]

except KeyError:

self.memoized[args] = self.function(*args)

return self.memoized[args]

@Memoize

def sum2x(n):

return sum(2 * i for i in range(n))

import time

def timed_func(func):

def timed(*args, **kwargs):

start = time.time()

result = func(*args, **kwargs)

elapsed = time.time() - start

print("time expired: {}".format(elapsed))

return result

return timed

@timed_func

@Memoize

def sum2x(n):

return sum(2 * i for i in range(n))