René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"BUG: Interactive mode slow","articleBody":"Based on `git bisect` it looks like #16028 caused a regression with interactive mode in Python 3.8, Qt5Agg backend (PyQt5=5.13.2), Linux x86_64  (at least; this is my system). The previous behavior (e.g., in 98aceb1cf032b315dbc9185821c2444c1de5698b) is that just doing:\r\n```\r\nimport matplotlib.pyplot as plt\r\nplt.ion()\r\nfig, ax = plt.subplots()\r\n```\r\nwould pop up a plot, and:\r\n\r\n- Typing in the terminal worked fine\r\n- Hitting ctrl-C (and then enter) had normal terminal behavior:\r\n    ```\r\n    \u003e\u003e\u003e\r\n    Traceback (most recent call last):\r\n      File \"\u003cstdin\u003e\", line 1, in \u003cmodule\u003e\r\n    KeyboardInterrupt\r\n    \u003e\u003e\u003e \r\n    ```\r\n\r\nBut in e6ffa5dd632f55d5f834d15e95547dd608a6bf35, I get:\r\n\r\n- Typing is very slow in the terminal (worsens with plot complexity)\r\n- Hitting ctrl-C kills the terminal:\r\n    ```\r\n    \u003e\u003e\u003e Traceback (most recent call last):\r\n      File \"/home/larsoner/python/matplotlib/lib/matplotlib/backends/backend_qt5.py\", line 507, in _draw_idle\r\n        self.draw()\r\n    ...\r\n      File \"/home/larsoner/python/matplotlib/lib/matplotlib/ticker.py\", line 2081, in __call__\r\n        return self.tick_values(vmin, vmax)\r\n      File \"/home/larsoner/python/matplotlib/lib/matplotlib/ticker.py\", line 2089, in tick_values\r\n        locs = self._raw_ticks(vmin, vmax)\r\n      File \"/home/larsoner/python/matplotlib/lib/matplotlib/ticker.py\", line 2045, in _raw_ticks\r\n        istep = np.nonzero(steps \u003e= raw_step)[0][0]\r\n    KeyboardInterrupt\r\n    Aborted\r\n    ```\r\n\r\nIf this description is not clear I could record some screen-cast GIFs or something.","author":{"url":"https://github.com/larsoner","@type":"Person","name":"larsoner"},"datePublished":"2020-01-22T19:02:37.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/16294/matplotlib/issues/16294"}