Simple process timer in python.

timer.py

from datetime import datetime
import time

class timer:
    def __enter__(self):
        self.start = datetime.now()
        return self

    def __exit__(self, type, value, traceback):
        self.end = datetime.now()
        print "time: %s" % (self.end - self.start)

with timer() as t:
    print "Hello, World!"
    time.sleep(2)