René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[Bug]: `rcdefaults` and `rcParams.clear()` don't work? ","articleBody":"### Bug summary\n\nThis is the `rcdefaults()` function\r\nhttps://github.com/matplotlib/matplotlib/blob/8faa835c81d9cf12342992521ddb95e9a645bc36/lib/matplotlib/__init__.py#L1068-L1091\r\n\r\nWhat exactly are we trying to do here? According to the docstring, if we're trying to reset the rcParams dictionary and only reset the keys that are not in `STYLE_BLACKLIST` then there are 2 problems I think:\r\n1. `rcParams.clear()` doesn't work. It doesn't clear out the entire dictionary.\r\n2. After the `update` line, `rcParams` will still have keys from `STYLE_BLACKLIST` which, if I were to perform the same operations on a dictionary, shouldn't be the case.\r\n3. While it does make sense to still have the keys from `STYLE_BLACKLIST` but then I'm not sure why `clear()` is used and not just directly update the keys.\r\n\r\nAlso, sidenote, `popitem()` errors out without a good error message (which is also why clear doesn't actually empty the dict?)\n\n### Code for reproduction\n\n```python\nIn [3]: mpl.rcParams[\"webagg.port\"]\r\nOut[3]: 8988\r\n\r\nIn [4]: mpl.rcParams[\"webagg.port\"] = 9000\r\n\r\nIn [5]: mpl.rcParams[\"webagg.port\"]\r\nOut[5]: 9000\r\n\r\nIn [6]: mpl.rcdefaults()\r\n\r\nIn [7]: mpl.rcParams[\"webagg.port\"]\r\nOut[7]: 9000\r\n\r\nIn [8]: mpl.rcParams.clear()\r\n\r\nIn [9]: mpl.rcParams[\"webagg.port\"]\r\nOut[9]: 9000\n```\n\n\n### Actual outcome\n\n`clear()` doesn't empty the `rcParams` dictionary.\n\n### Expected outcome\n\n`clear()` should empty the dictionary and after `rcdefaults()`, keys from `STYLE_BLACKLIST` shouldn't be there.\n\n### Additional information\n\nI'm not sure if this is a documentation issue and the behaviour is intended or the behaviour isn't intended.\n\n### Operating system\n\n_No response_\n\n### Matplotlib Version\n\nCurrent main\n\n### Matplotlib Backend\n\n_No response_\n\n### Python version\n\n_No response_\n\n### Jupyter version\n\n_No response_\n\n### Installation\n\nNone","author":{"url":"https://github.com/chahak13","@type":"Person","name":"chahak13"},"datePublished":"2023-05-11T04:40:21.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":9},"url":"https://github.com/25855/matplotlib/issues/25855"}