René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[MNT]: User feedback should use warnings, not logs","articleBody":"### Summary\r\n\r\nThere are at least two places where matplotlib provides a message to the user about usage patterns that are potentially mistakes using logging functionality, rather than as a warning.\r\n\r\nTwo examples I've encountered recently:\r\n\r\n- [Passing string-formatted numbers as data](https://github.com/matplotlib/matplotlib/blob/v3.5.2/lib/matplotlib/category.py#L234-L237)\r\n- [Done] \u003cs\u003e[Passing an RGB tuple to the `c` parameter of `scatter`](https://github.com/matplotlib/matplotlib/blob/v3.5.2/lib/matplotlib/axes/_axes.py#L4203-L4210)\u003c/s\u003e\r\n\r\nI don't think logging is the right mechanism here:\r\n\r\n- The feedback provides very little information about the source of the problem, you just get some text in stderr.\r\n- Related, you can convert a warning to an error and then drop into a debugger to figure out what's happening; I don't think that's the case with logging?\r\n- Warnings can be intercepted by third party libraries that are doing something on purpose (i.e., passing numbers-as-strings to use a categorical axis), whereas logs are harder to muffle without intervening.\r\n\r\n### Proposed fix\r\n\r\nIt's possible I am wrong here, but `warnings.warn` feels like the right mechanism for both of these pieces of feedback.","author":{"url":"https://github.com/mwaskom","@type":"Person","name":"mwaskom"},"datePublished":"2022-07-12T22:41:21.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":42},"url":"https://github.com/23422/matplotlib/issues/23422"}