sample.py

import logging
import os
import sys
import time

from logging_spinner import SpinnerHandler, UserWaitingFilter


logger = logging.getLogger('sample')


def sample_program(interval):
    l = logger.getChild('sample_program')

    l.debug('sample_program() was called.')
    # Log records without "user_waiting" extra field are ignored by
    # logging-spinner.

    l.info("Let's get started!", extra={'user_waiting': True})
    # The "user_waiting" extra field is used by logging-spinner.
    # "True" indicates a user need to wait until a process is finished.
    time.sleep(interval)  # Some time-taking process

    l.info("Still processing...", extra={'user_waiting': True})
    # Log records with {'user_waiting': True} can be continuous
    # in order to represent phase changes.
    time.sleep(interval)

    l.info("Done!", extra={'user_waiting': False})
    # Log records with {'user_waiting': False} indicates a time-taking process
    # is just finished so that a user don't have to wait now.

    # extra={'user_waiting': True}  -> show a spinner
    # extra={'user_waiting': False} -> hide a spinner


def main(stream=sys.stdout):
    interval = float(sys.argv[1]) if len(sys.argv) > 1 else 2

    # Setup a SpinnerHandler to application logger(s)
    handler = SpinnerHandler(stream=stream)
    logger.addHandler(handler)
    logger.setLevel(logging.INFO)

    # If a StreamHandler is also installed together it should filter
    # log records with "user_waiting" extra field so that these log messages
    # won't be printed twice (with a spinner, and without a spinner again).
    if os.environ.get('DEBUG') in ('yes', 'y', '1', 'true'):
        stream_handler = logging.StreamHandler(stream=stream)
        stream_handler.addFilter(UserWaitingFilter())
        stream_handler.setLevel(logging.DEBUG)
        logger.addHandler(stream_handler)
        logger.setLevel(logging.DEBUG)

    sample_program(interval=interval)


if __name__ == '__main__':
    main()