gistfile1.py

import time

def get_sources():
    for i in xrange(100000):
       yield i

class get_sources2(object):
    def __init__(self):
        self.range_iter = xrange(100000).__iter__()

    def __iter__(self):
        return self

    def __hasnext__(self):
        return self.range_iter.__hasnext__()

    def next(self):
        return self.range_iter.next()

def test_impl(impl, msg):
    low_watermark = 100000
    iter_count = 0

    for s in xrange(100000):
        start = time.time()
        sum = 0
        for i in impl():
            sum = sum + i
        elapsed = time.time() - start
        if elapsed < low_watermark:
            iter_count = 0
            low_watermark = elapsed
        iter_count = iter_count + 1
        if iter_count == 100:
            print "%s: %4.1fus" % (msg, elapsed * 1000000.0,)
            return


test_impl(get_sources, "for-yield loop")
test_impl(get_sources2, "iterable class with __hasnext__")

# python output:
# for-yield loop: 5727.1us
# iterable class with __hasnext__: 21207.1us

# pyston_release output
# for-yield loop: 16795.2us
# iterable class with __hasnext__: 9035.8us