René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"logging.config.dictConfig() with \"disable_existing_loggers=False\" closes existing handlers","articleBody":"# Bug report\n\n### Bug description:\n\nInvoking `logging.config.dictConfig()` with `\"disable_existing_loggers\": False` breaks already added handlers, even if the config is empty. Specifically, it calls `flush()` and `close()` of all existing handlers.\n\nTest script:\n\n```python\nimport logging\nimport logging.config\n\n# test setup: add a FileHandler as the only handler of the root logger\nfileHandler = logging.FileHandler(\"./debug_log.txt\", mode=\"w\")\nfileHandler.setFormatter(logging.Formatter(\"%(message)s\"))\nroot_logger = logging.getLogger()\nroot_logger.addHandler(fileHandler)\n\n# this works fine - the message is added to the file\nlogging.warning(\"test message 1\")\n\n# set a trivial configuration: no formatters, handlers or loggers.\n# \"disable_existing_loggers\" is set to False\nlogging.config.dictConfig({\"version\": 1, \"disable_existing_loggers\": False})\n\n# the FileHandler doesn't work anymore - this message won't be added to the file\nlogging.warning(\"test message 2\")\n\n# the handler is in inconsistent state - it's still added to the logger,\n# but it's already flush()'ed and close()'d\nassert fileHandler in root_logger.handlers\nassert fileHandler._closed == True\n```\n\nThe content of the `debug_log.txt` after running this script is the following:\n```\ntest message 1\n```\n\nBut it supposed to be\n```\ntest message 1\ntest message 2\n```\n\nMaybe issue #123239 is somehow related.\n\n### CPython versions tested on:\n\n3.13\n\n### Operating systems tested on:\n\nmacOS\n\n\u003c!-- gh-linked-prs --\u003e\n### Linked PRs\n* gh-127690\n\u003c!-- /gh-linked-prs --\u003e\n","author":{"url":"https://github.com/aparshin","@type":"Person","name":"aparshin"},"datePublished":"2024-12-03T15:38:44.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":13},"url":"https://github.com/127567/cpython/issues/127567"}