René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"`matplotlib\u003e=3.3.2` breaks `ipywidgets.interact`","articleBody":"### Bug report\r\n\r\n**Bug summary**\r\n\r\nUsing `ipywidgets.interact` to update a figure works as expected in `matplotlib\u003c=3.3.1`, but fails in `matplotlib==3.3.2`.\r\n\r\nI don't think this is an `ipywidgets` issue since downgrading `matplotlib` fixes this issue.\r\n\r\n**Code for reproduction**\r\n\r\nIn[1]:\r\n```python\r\n%matplotlib notebook\r\nimport matplotlib as mpl\r\nimport matplotlib.pyplot as plt\r\nimport ipywidgets as ipyw\r\n\"works if %s \u003c= 3.3.1\" % mpl.__version__\r\n```\r\nIn[2]:\r\n```python\r\nfig = plt.figure()\r\n@ipyw.interact(m=ipyw.FloatSlider(value=1, min=-10, max=10, step=0.01))\r\ndef update(m):\r\n    plt.figure(fig.number, clear=True)\r\n    plt.plot([m * x for x in range(-9, 10)])\r\n```\r\n\r\nFollowed by moving the slider.\r\n\r\n**Actual outcome**\r\n\r\n- when moving the slider, the figure does not update\r\n- a second figure is sometimes created instead\r\n- the second figure is usually blank, but sometimes updates instead\r\n\r\n**Expected outcome**\r\n\r\n- the original figure updates as it does in `matplotlib==3.3.1`\r\n\r\n**Matplotlib version**\r\n\u003c!--Please specify your platform and versions of the relevant libraries you are using:--\u003e\r\n  * Operating system: Ubuntu\r\n  * Matplotlib version: 3.3.2 vs 3.3.1\r\n  * Matplotlib backend (`print(matplotlib.get_backend())`): nbAgg\r\n  * Python version: 3.7.8\r\n  * Jupyter version (if applicable): jupyter-core==4.6.3\r\n  * Other libraries: ipywidgets==7.5.1\r\n  * Installation source: `conda` channel `conda-forge`\r\n","author":{"url":"https://github.com/casperdcl","@type":"Person","name":"casperdcl"},"datePublished":"2020-10-02T19:24:07.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":8},"url":"https://github.com/18638/matplotlib/issues/18638"}