Python logging tips

logging_tips.py

import sys
import logging

# 1 - Choose a logger (where logs should come from)
# logger = logging.getLogger()  # Root logger ; if you're in a notebook of end-user script
logger = logging.getLogger(__name__)  # Lib-named logger ; if you're in a module
# logger = logging.getLogger(None if __name__=='__main__' else __name__)

# 2 - Choose the (minimal) log level
logger.setLevel(logging.DEBUG)

# 3 - Create one (or several handlers)
if True:
    # 3-a - Choose where logs should go
    log_handler = logging.StreamHandler()  # Default ; log to formatted (pink) space in notebooks
    # log_handler = logging.StreamHandler(stream=sys.stdout)  # Log to the console
    # log_handler = logging.FileHandler(filename='./logs.log', mode='a')  # Log to a file
    # import io
    # io = io.StringIO()
    # log_handler = logging.StreamHandler(stream=io)  # Logs to io.StringIO

    # 3-b - Choose the log level (>= logger.level)
    log_handler.setLevel(logging.WARNING)

    # 3-c - Choose the log format
    log_handler.setFormatter(logging.Formatter(
        '%(asctime)s (%(name)s:%(filename)s:%(lineno)s)- %(levelname)s - %(message)s'))

    # 3-d - Add the handler to the logger
    logger.addHandler(log_handler)