René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[Bug]: Figures fail to redraw with IPython","articleBody":"### Bug summary\n\nA regression between release versions 3.5.1 and 3.5.2 causes figures to fail to redraw after an initial plot is added using the `pyplot` interface in an interactive IPython session. This has been observed with both `pyplot.plot` and `pyplot.tripcolor`. The figure will show the first plot drawn, but subsequent calls to `pyplot.plot` and `pyplot.tripcolor` fail to update an on-screen figure until `pyplot.draw` is invoked. This has been observed with IPython versions 8.3.0 (current) and 8.2.0.\r\n\r\nBoth the Qt5 and Tk backends exhibit the same issues.\n\n### Code for reproduction\n\n```python\n# Install matplotlib and ipython in a virtualenv\r\npython3 -m venv ~/mpl.venv\r\n. ~/mpl.venv/bin/activate\r\npip install matplotlib ipython\r\n\r\n# Make sure to start with a clean config\r\nmv ~/.ipython ~/.ipython.backup\r\nmv ~/.config/matplotlib .config/matplotlib.backup\r\n\r\n# Run `pylab`\r\nipython --pylab=tk\r\n\r\n# ... the following are commands issues in the ipython prompt\r\nplot(arange(10))\r\nplot(-arange(10))\r\ndraw()\n```\n\n\n### Actual outcome\n\n1. After the first `plot` command, a figure appears with a `y = x` line shown.\r\n2. After the second `plot` command, the figure does not update.\r\n3. After the `draw` command, the figure updates to show both the `y = x` and `y = -x` lines.\n\n### Expected outcome\n\n1. After the first `plot` command, a figure appears with a `y = x` line shown. (This is as expected.)\r\n2. After the second `plot` command, the figure updates with the addition of a `y = -x` line. (This is the deviation.)\r\n3. The `draw` command should produce no visible change in the figure.\n\n### Additional information\n\nThis regression has been bisected to commit f937b0ab5ef9d5ffe9f2f58f6391357783cc4afa.\r\n\r\nThe testbed is a current Void Linux system running Python 3.10.4, including the system `python3-tkinter` package for a GUI. (As noted above, this bug is also present with the Qt5 backend.) All packages were installed in a virtual environment. The output of `pip freeze` is:\r\n\r\n```\r\nasttokens==2.0.5\r\nbackcall==0.2.0\r\ncycler==0.11.0\r\ndecorator==5.1.1\r\nexecuting==0.8.3\r\nfonttools==4.33.3\r\nipython==8.3.0\r\njedi==0.18.1\r\nkiwisolver==1.4.2\r\nmatplotlib==3.6.0.dev155+gf937b0ab5e\r\nmatplotlib-inline==0.1.3\r\nnumpy==1.22.3\r\npackaging==21.3\r\nparso==0.8.3\r\npexpect==4.8.0\r\npickleshare==0.7.5\r\nPillow==9.1.0\r\nprompt-toolkit==3.0.29\r\nptyprocess==0.7.0\r\npure-eval==0.2.2\r\nPygments==2.12.0\r\npyparsing==3.0.9\r\npython-dateutil==2.8.2\r\nsetuptools-scm==6.4.2\r\nsix==1.16.0\r\nstack-data==0.2.0\r\ntk==0.1.0\r\ntomli==2.0.1\r\ntraitlets==5.2.0\r\nwcwidth==0.2.5\r\n```\r\n(Note that the funny `matplotlib` version comes from a local git repo checked out to the problematic commit.)\n\n### Operating system\n\nVoid Linux x86_64\n\n### Matplotlib Version\n\n3.5.2\n\n### Matplotlib Backend\n\nTkAgg, Qt5Agg\n\n### Python version\n\n3.10.4\n\n### Jupyter version\n\nNone\n\n### Installation\n\npip","author":{"url":"https://github.com/ahesford","@type":"Person","name":"ahesford"},"datePublished":"2022-05-13T02:32:40.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":8},"url":"https://github.com/23042/matplotlib/issues/23042"}