Demonstration of hang when coloredlogs in one thread and import in other thread does logging

hang_coloredlogs.py

#!/usr/bin/env python

import logging
import time
import threading
import coloredlogs

# configured notices that will be displayed with styling by coloredlogs
NOTICE = 25
logging.addLevelName(25, 'notice')

def background_thread():
    time.sleep(1)
    logging.log(NOTICE, "background thread is progressing")
    logging.info("Time to say goodbye")
    return

def main_thread():
    coloredlogs.install(level='INFO')
    background = threading.Thread(target=background_thread)
    try:
        background.start()
        logging.info("Main thread doing import")
        import hang_helper1
        logging.info("Main thread completed import")
    finally:
        background.join()

if __name__ == '__main__':
    main_thread()

hang_helper1.py

#!/usr/bin/env python

import time
import logging

# simulate a slow and more complicated import, that also does some logging
for n in range(10):
    logging.info("Time is ticking away")
    time.sleep(1)