An example of single callable that works as both a contextmanager and a decorator

log_time_contextdecorator.py

import logging
import sys
import contextlib
from timeit import default_timer as timer
from typing import Any

root = logging.getLogger()
root.setLevel(logging.DEBUG)

handler = logging.StreamHandler(sys.stdout)
handler.setLevel(logging.DEBUG)
formatter = logging.Formatter(
    '%(asctime)s - %(name)s - %(levelname)s - %(message)s')
handler.setFormatter(formatter)
root.addHandler(handler)


class log_time(contextlib.ContextDecorator):
    def __init__(self, logger, level='info', event=None):
        self.logger = logger
        self.level = level
        self.event = event

    def __enter__(self):
        self.start = timer()
        getattr(self.logger, self.level.lower(),
                'info')(f'{self.event} started')

    def __exit__(self, *exc):
        getattr(self.logger, self.level.lower(), 'info')(
            f'{self.event} finished. Took {timer() - self.start:.3f} seconds')

    def __call__(self, func):
        self.event = func.__qualname__
        return super().__call__(func)


@log_time(logger=root)
def log_time_for_log_time(who):
    print(f' >>>>>>> {who} <<<<<<< ')


if __name__ == '__main__':
    with log_time(logger=root, event='log time for log_time_for_log_time'):
        log_time_for_log_time('tester')