Timing context

timing_context.py

from collections import OrderedDict

class TimerContext(object):
    def __init__(self, name, callback):
        self._name = name
        self._callback = callback
        self._start = None

    def __enter__(self):
        self._start = time.time()

    def __exit__(self, *ignored):
        elapsed = time.time() - self._start
        self._callback(self._name, elapsed)


class MultiTimer(object):
    def __init__(self):
        self.timers = OrderedDict()

    def __getitem__(self, name):
        self.timers[name] = None  # for OrderedDict order..
        return TimerContext(name, self.__setitem__)

    def __setitem__(self, name, value):
        self.timers[name] = value


## Example usage:
timer = MultiTimer()

with timer["my_timer"]:
    do_something()

with timer["my_timer2"]:
    for x in xrange(100000):
        do_something_else()


print "----"
for key, value in timer.timers.iteritems():
    print "{}: {:.3f}".format(key, value)