Python stop watch

stop_watch.py

from time import time


class StopWatch:
    def __init__(self):
        self.start_time = 0
        self.stop_time = 0
        self.total_time = 0

    def __enter__(self) -> "StopWatch":
        self.start()
        return self

    def __exit__(self, exc_type, exc_val, exc_tb) -> "StopWatch":
        self.stop()
        return self

    def is_stopped(self) -> bool:
        if self.total_time:
            return True

        return False

    def elapsed_time(self) -> int:
        if self.is_stopped():
            return self.total_time

        return time() - self.start_time

    def start(self) -> None:
        self.start_time = time()

    def stop(self) -> None:
        self.stop_time = time()
        self.total_time = self.stop_time - self.start_time


# Sample use case
def main():
    with StopWatch() as stop_watch:
        print("processing...")
        # main logic

    # Check total time main logic took
    print(stop_watch.elapsed_time())

    with StopWatch() as stop_watch:
        while True:
            print("Hello.")

            # You can check duration from inside 'with' block
            if stop_watch.elapsed_time() > 3:
                break

    print(stop_watch.elapsed_time())


if __name__ == "__main__":
    main()