gistfile1.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import time

class Timer(object):
    def __init__(self, verbose=False):
        self.verbose = verbose

    def __enter__(self):
        self.start = time.time()
        return self

    def __exit__(self, *args):
        self.end = time.time()
        self.secs = self.end - self.start
        self.msecs = self.secs * 1000  # millisecs
        if self.verbose:
            print 'elapsed time: %f ms' % self.msecs


with Timer() as t:
    i = 0
    while i < 1000000:
        print i
        i += 1
print 'while =', t.secs

with Timer() as t:
    for i in range(1000000):
        print i
print 'for =', t.secs