A simple stopwatch object that mimics Matlab's tic - toc pair

tictoc.py

import time


class TicToc:
    """ A simple stopwatch object"""
    def __init__(self, name=None, start=True):
        if name is None:
            name = 'Running time'
        self.name = name
        self.dt = 0.0
        self._t_start = None
        self.state = 'off'
        if start is True:
            self.start()

    def tic(self):
        """ Start and return self"""
        self._t_start = time.time()
        self.dt = 0
        self.state = 'on'
        return self

    def start(self):
        return self.tic()

    def toc(self):
        """ Stop and return self's string representation """
        self.stop()
        return self.__str__()


    def stop(self):
        assert self.state == 'on'
        t_stop = time.time()
        self.state = 'off'
        dt = t_stop - self._t_start
        self.dt += dt
        self._t_start = None
        return self

    def restart(self):
        if self.is_running():
            self.stop()
        return self.tic()

    def running_time(self):
        if self.state == 'on':
            t_curr = time.time()
            dt = t_curr - self._t_start
            dt += self.dt
        else:
            dt = self.dt
        return dt


    def is_running(self):
        return self.state == 'on'

    def __str__(self):
        SECONDS_PER_MINUTE = 60.
        SECONDS_PER_HOUR = 60. * SECONDS_PER_MINUTE
        dt = self.running_time()
        int_hours = int(dt / SECONDS_PER_HOUR)
        minutes = (dt - int_hours * SECONDS_PER_HOUR) / SECONDS_PER_MINUTE
        int_minutes = int(minutes)
        seconds = dt - int_hours * SECONDS_PER_HOUR - int_minutes * SECONDS_PER_MINUTE
        if int_hours > 0:
            ret = '%02d:%02d:%04.1f' % (int_hours, int_minutes, seconds)
        else:
            ret = '%02d:%04.1f' % (int_minutes, seconds)
        if bool(self.name):
            ret = '%s: %s' % (self.name, ret)
        return ret