René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Memory leaks on matplotlib 3.4.2 (and 3.4.0)","articleBody":"\u003c!--To help us understand and resolve your issue, please fill out the form to the best of your ability.--\u003e\r\n\u003c!--You can feel free to delete the sections that do not apply.--\u003e\r\n\r\n### Bug report\r\n\r\n\r\n**Bug summary**\r\n\r\nMultiple different memory related errors when running as a part of script creating and saving lots of figures.\r\n\r\n\r\n**Code for reproduction**\r\n\r\nSorry, could not create a minimal example that reproduces this. Just wanted to leave a note. \r\n\r\n\r\n\r\n**Actual outcome**\r\n\r\nThere are multiple different errors that happen. Running the same script will produce different results randomly.\r\n\r\n\u003c!--The output produced by the above code, which may be a screenshot, console output, etc.--\u003e\r\n\r\n**Example 1**\r\nJust prints this. No Exceptions, nothing. Script stops running.\r\n```\r\nunable to alloc 4320000 bytes\r\n```\r\n\r\n**Example 2** \r\n\r\n```python\r\n  File \"c:\\myapp\\calculations\\myscript.py\", line 422, in create_figure\r\n    fig, ax = plt.subplots(nrows=1, figsize=(16, 9))\r\n  File \"C:\\Python\\venvs\\adiapp\\lib\\site-packages\\matplotlib\\_api\\deprecation.py\", line 471, in wrapper\r\n    return func(*args, **kwargs)\r\n  File \"C:\\Python\\venvs\\adiapp\\lib\\site-packages\\matplotlib\\pyplot.py\", line 1439, in subplots\r\n    fig = figure(**fig_kw)\r\n  File \"C:\\Python\\venvs\\adiapp\\lib\\site-packages\\matplotlib\\pyplot.py\", line 797, in figure\r\n    manager = new_figure_manager(\r\n  File \"C:\\Python\\venvs\\adiapp\\lib\\site-packages\\matplotlib\\pyplot.py\", line 316, in new_figure_manager\r\n    return _backend_mod.new_figure_manager(*args, **kwargs)\r\n  File \"C:\\Python\\venvs\\adiapp\\lib\\site-packages\\matplotlib\\backend_bases.py\", line 3545, in new_figure_manager\r\n    return cls.new_figure_manager_given_figure(num, fig)\r\n  File \"C:\\Python\\venvs\\adiapp\\lib\\site-packages\\matplotlib\\backends\\_backend_tk.py\", line 899, in new_figure_manager_given_figure\r\n    canvas = cls.FigureCanvas(figure, master=window)\r\n  File \"C:\\Python\\venvs\\adiapp\\lib\\site-packages\\matplotlib\\_api\\deprecation.py\", line 431, in wrapper\r\n    return func(*inner_args, **inner_kwargs)\r\n  File \"C:\\Python\\venvs\\adiapp\\lib\\site-packages\\matplotlib\\backends\\_backend_tk.py\", line 174, in __init__\r\n    self._tkphoto = tk.PhotoImage(\r\n  File \"C:\\Python\\Python 3.8.6-32\\lib\\tkinter\\__init__.py\", line 4061, in __init__\r\n    Image.__init__(self, 'photo', name, cnf, master, **kw)\r\n  File \"C:\\Python\\Python 3.8.6-32\\lib\\tkinter\\__init__.py\", line 4006, in __init__\r\n    self.tk.call(('image', 'create', imgtype, name,) + options)\r\n_tkinter.TclError: not enough free memory for image buffer\r\n```\r\n\r\n**Example 3**\r\n\r\n```python\r\n  File \"c:\\myapp\\calculations\\myscript.py\", line 467, in create_some_figures\r\n    plt.savefig(self.folder / \"myfig.png\")\r\n  File \"C:\\Python\\venvs\\adiapp\\lib\\site-packages\\matplotlib\\pyplot.py\", line 966, in savefig\r\n    res = fig.savefig(*args, **kwargs)\r\n  File \"C:\\Python\\venvs\\adiapp\\lib\\site-packages\\matplotlib\\figure.py\", line 3005, in savefig\r\n    self.canvas.print_figure(fname, **kwargs)\r\n  File \"C:\\Python\\venvs\\adiapp\\lib\\site-packages\\matplotlib\\backend_bases.py\", line 2255, in print_figure\r\n    result = print_method(\r\n  File \"C:\\Python\\venvs\\adiapp\\lib\\site-packages\\matplotlib\\backend_bases.py\", line 1669, in wrapper\r\n    return func(*args, **kwargs)\r\n  File \"C:\\Python\\venvs\\adiapp\\lib\\site-packages\\matplotlib\\backends\\backend_agg.py\", line 508, in print_png\r\n    FigureCanvasAgg.draw(self)\r\n  File \"C:\\Python\\venvs\\adiapp\\lib\\site-packages\\matplotlib\\backends\\backend_agg.py\", line 401, in draw\r\n    self.renderer = self.get_renderer(cleared=True)\r\n  File \"C:\\Python\\venvs\\adiapp\\lib\\site-packages\\matplotlib\\backends\\backend_agg.py\", line 417, in get_renderer\r\n    self.renderer = RendererAgg(w, h, self.figure.dpi)\r\n  File \"C:\\Python\\venvs\\adiapp\\lib\\site-packages\\matplotlib\\backends\\backend_agg.py\", line 91, in __init__\r\n    self._renderer = _RendererAgg(int(width), int(height), dpi)\r\nMemoryError: In RendererAgg: Out of memory\r\n```\r\n\r\n**Expected outcome**\r\n\r\n\u003c!--A description of the expected outcome from the code snippet--\u003e\r\n\u003c!--If this used to work in an earlier version of Matplotlib, please note the version it used to work on--\u003e\r\nNo errors. \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:  Windows 10\r\n  * Matplotlib version (`import matplotlib; print(matplotlib.__version__)`): 3.4.2\r\n  * Matplotlib backend (`print(matplotlib.get_backend())`): TkAgg \r\n  * Python version: 32-bit 3.8.6 \r\n\r\n\r\n\u003c!--Please tell us how you installed matplotlib and python e.g., from source, pip, conda--\u003e\r\n\u003c!--If you installed from conda, please specify which channel you used if not the default--\u003e\r\n\r\n\r\n## Workaround\r\n\r\nAs a side note, tried on **version 3.3.4** and everything works. Does not work on 3.4.0. I'm calling \r\n\r\n```python\r\n        plt.close(\"all\")\r\n        plt.close()\r\n        gc.collect()\r\n```\r\nafter every `plt.savefig()` just to be sure.\r\n","author":{"url":"https://github.com/fohrloop","@type":"Person","name":"fohrloop"},"datePublished":"2021-06-23T08:02:38.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":10},"url":"https://github.com/20490/matplotlib/issues/20490"}