source: doc/theses/andrew_beach_MMath/code/throw-with.py @ fa5e1aa5

#!/usr/bin/env python3

# Throw Across With Statement (closest thing Python has to a destructor)

from time import thread_time_ns


class EmptyException(Exception):
    pass


class EmptyContextManager:

    def __enter__(self):
        pass

    def __exit__(self, exception_type, exception_value, traceback):
        pass


def unwind_with(frames):
    if 0 < frames:
        with EmptyContextManager():
            unwind_with(frames - 1)
    else:
        raise EmptyException()


def main(argv):
    times = 1
    total_frames = 1
    if 1 < len(argv):
        times = int(argv[1])
    if 2 < len(argv):
        total_frames = int(argv[2])

    start_time = thread_time_ns()
    for count in range(times):
        try:
            unwind_with(total_frames)
        except EmptyException:
            pass

    end_time = thread_time_ns()
    print('Run-Time (s): {:.1f}'.format((end_time - start_time) / 1_000_000_000.))


if '__main__' == __name__:
    import sys
    main(sys.argv)