simple python context manager for measuring time

clockit.py

import time
import sys
from contextlib import contextmanager

@contextmanager
def clockit(msg):
    s = time.clock()
    yield
    print("** %s: %.03f" % (msg, time.clock() - s), file=sys.stderr)


if __name__ == '__main__':
    print("hello this is a cool program")

    print("small multiplication is fast")

    print(" - starting small mul")
    s = 1
    for n in range(1,100):
        s *= n
    print(" - finished small mul")

    print("but big multiplication is slooow")

    print(" - starting big mul")

    with clockit('big multiplication'):
        s = 1
        for n in range(1,100000):
            s *= n

    print(" - finished big mul")

    print("see?")