⏱️ listwatch -- a classy stopwatch for Python 3.3+

stopwatch1.py

"""
stopwatch1.py -- a classy stopwatch for Python 3.3+

Copyright (c) 2020, Nebil Kawas García
This source code is subject to the terms of the Mozilla Public License.
You can obtain a copy of the MPL at <https://www.mozilla.org/MPL/2.0/>.
"""

from datetime import datetime


class Stopwatch:
    """
    A minimalist stopwatch with a single-list approach.
    """

    def __init__(self):
        self.reset()

    def reset(self):
        self._timestamps = []

    @staticmethod
    def now():
        return datetime.now().timestamp()

    def switch(self):
        self._timestamps.append(self.now())

    @property
    def is_ticking(self):
        return len(self._timestamps) % 2 == 1

    @property
    def elapsed_time(self):
        pauses = sum(self._timestamps[1::2], self.is_ticking * self.now())
        starts = sum(self._timestamps[0::2])
        return pauses - starts

    def __str__(self):
        return "{:.2f} seconds".format(self.elapsed_time)


if __name__ == "__main__":
    watch = Stopwatch()
    print(watch)
    print(watch.is_ticking)

stopwatch2.py

"""
stopwatch2.py -- a classy stopwatch for Python 3.3+

Copyright (c) 2020, Nebil Kawas García
This source code is subject to the terms of the Mozilla Public License.
You can obtain a copy of the MPL at <https://www.mozilla.org/MPL/2.0/>.
"""

from datetime import datetime


class Stopwatch:
    """
    A minimalist stopwatch with a double-list approach.
    """

    def __init__(self):
        self.reset()

    def reset(self):
        self._pauses = []
        self._starts = []

    @staticmethod
    def now():
        return datetime.now().timestamp()

    def switch(self):
        if self.is_ticking:
            self._pauses.append(self.now())
        else:
            self._starts.append(self.now())

    @property
    def is_ticking(self):
        return len(self._pauses) != len(self._starts)

    @property
    def elapsed_time(self):
        pauses = sum(self._pauses, self.is_ticking * self.now())
        starts = sum(self._starts)
        return pauses - starts

    def __str__(self):
        return "{:.2f} seconds".format(self.elapsed_time)


if __name__ == "__main__":
    watch = Stopwatch()
    print(watch)
    print(watch.is_ticking)