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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"PGF backend + savefig.bbox results in I/O error in 3.2","articleBody":"### Bug report\r\n\r\n**Bug summary**\r\n\r\nWhen using matplotlib 3.2, the PGF backend and the rcParam \"savefig.bbox\" set to \"tight\", `plt.savefig` error with `ValueError: I/O operation on closed file.` Works fine on 3.1.3.\r\n\r\n**Code for reproduction**\r\n\r\n```python\r\nimport matplotlib as mpl\r\nmpl.use(\"pgf\")\r\nimport matplotlib.pyplot as plt\r\nplt.rcParams.update({\"pgf.texsystem\": \"lualatex\", \"savefig.bbox\": \"tight\"})\r\nfig, ax = plt.subplots()\r\nax.plot([1.0, 2.0, 3.0], [4.0, 5.0, 6.0])\r\nplt.savefig(\"test.pdf\")\r\n```\r\nI don't know if the lualatex is necessary to reproduce, I just didn't have xelatex installed. Without the savefig.bbox it works fine.\r\n\r\n**Actual outcome**\r\n\r\n~~~\r\nTraceback (most recent call last):\r\n  File \"test.py\", line 9, in \u003cmodule\u003e\r\n    plt.savefig(\"test.pdf\")\r\n  File \"/usr/local/lib/python3.7/dist-packages/matplotlib/pyplot.py\", line 723, in savefig\r\n    res = fig.savefig(*args, **kwargs)\r\n  File \"/usr/local/lib/python3.7/dist-packages/matplotlib/figure.py\", line 2203, in savefig\r\n    self.canvas.print_figure(fname, **kwargs)\r\n  File \"/usr/local/lib/python3.7/dist-packages/matplotlib/backend_bases.py\", line 2067, in print_figure\r\n    self.figure.draw(renderer)\r\n  File \"/usr/local/lib/python3.7/dist-packages/matplotlib/artist.py\", line 38, in draw_wrapper\r\n    return draw(artist, renderer, *args, **kwargs)\r\n  File \"/usr/local/lib/python3.7/dist-packages/matplotlib/figure.py\", line 1734, in draw\r\n    self.patch.draw(renderer)\r\n  File \"/usr/local/lib/python3.7/dist-packages/matplotlib/artist.py\", line 38, in draw_wrapper\r\n    return draw(artist, renderer, *args, **kwargs)\r\n  File \"/usr/local/lib/python3.7/dist-packages/matplotlib/patches.py\", line 602, in draw\r\n    self._facecolor if self._facecolor[3] else None)\r\n  File \"/usr/local/lib/python3.7/dist-packages/matplotlib/backends/backend_pgf.py\", line 476, in draw_path\r\n    writeln(self.fh, r\"\\begin{pgfscope}\")\r\n  File \"/usr/local/lib/python3.7/dist-packages/matplotlib/backends/backend_pgf.py\", line 118, in writeln\r\n    fh.write(line)\r\nValueError: I/O operation on closed file.\r\n~~~\r\n\r\n**Expected outcome**\r\n\r\nWorks in 3.1.3.\r\n\r\n**Matplotlib version**\r\n  * Operating system: Debian Stable\r\n  * Matplotlib version: 3.2\r\n  * Matplotlib backend (`print(matplotlib.get_backend())`): pgf\r\n  * Python version: 3.7\r\n\r\nInstalled matplotlib from pip.","author":{"url":"https://github.com/Psirus","@type":"Person","name":"Psirus"},"datePublished":"2020-03-11T11:55:31.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":7},"url":"https://github.com/16731/matplotlib/issues/16731"}