Sample python watchdog

main.py

import time
import subprocess
from watchdog.events import PatternMatchingEventHandler
from watchdog.observers import Observer


class TestFileWatchEventHandler(PatternMatchingEventHandler):
    def __run_test(self):
        subprocess.call('python3 -m unittest discover ./tests', shell=True)

    def on_created(self, event):
        self.__run_test()

    def on_modified(self, event):
        self.__run_test()

    def on_moved(self, event):
        self.__run_test()


if __name__ == '__main__':
    event_handler = TestFileWatchEventHandler(
            patterns=['*.py'])
    observer = Observer()
    observer.schedule(event_handler, './tests', recursive=True)
    observer.start()
    print('Watching test files...')

    try:
        while True:
            time.sleep(1)
    except KeyboardInterrupt:
        observer.stop()
    observer.stop()
    print('Stop watch test files')