This library helps to display loading spinners in CLI in non-intrusive manner. Applications/libraries don't have to depend on any third-party API, but only need to log loading messages through Python's standard logging library:

logger = logging.getLogger('myapp.logger')
logger.info('Loading data...', extra={'user_waiting': True})
# some long taking process goes here...
logger.info('Finished loading!', extra={'user_waiting': False})

At the outest code of the application, setup a SpinnerHandler:

from logging_spinner import SpinnerHandler

logger = logging.getLogger('myapp')
logger.setLevel(logging.INFO)
logger.addHandler(SpinnerHandler())

SpinnerHandler is only aware of log records with user_waiting extra field and displays them with a spinner.

See also sample.py code.

Written by Hong Minhee and distributed under GPLv3 or later.

Released on June 22, 2017.

• Fixed a ValueError raised when a log record with {'user_waiting': Flase} is made without any previous log records with {'user_waiting': True}.

Released on May 21, 2017.

• Fixed a bug that SpinerHandler had crashed when user_waiting log records show a spinner again after a previous spinner was hidden.

Released on May 21, 2017.

• logging_spinner.UserWaitingFilter was introduced to avoid duplicate prints of a log record with user_waiting extra field.

Released on May 21, 2017. The initial release.