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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Memory leak when plotting multiple figures with the macOS backend","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**Bug summary**\r\n\r\nHi,\r\n\r\nI believe I have found a memory issue when plotting multiple figures with the macOS backend.\r\n\r\nHere is a minimal working example:\r\n\r\n```python\r\nimport sys\r\nimport matplotlib.pyplot as plt\r\nimport numpy as np\r\n\r\nimport matplotlib\r\n#matplotlib.use('agg')\r\n\r\ndata = np.random.rand(60, 60)\r\n\r\ndef plot_expr(plot_name):\r\n\r\n    plt.figure(figsize=(9, 8))\r\n\r\n    for i in range(60):\r\n        plt.plot(data[i, :])\r\n\r\n    plt.savefig(plot_name)\r\n\r\n    plt.close('all')\r\n\r\n\r\nif __name__ == \"__main__\":\r\n\r\n    print(f'python: {sys.version}')\r\n    print(f'matplotlib: {matplotlib.__version__}')\r\n    print(f'backend: {matplotlib.get_backend()}')\r\n\r\n    for i in range(50):\r\n        print(f'{i}...')\r\n        plot_expr(f'leak_{i}')\r\n```\r\n\r\nWhen running the code with `memory-profiler`, I obtain something like:\r\n![leak](https://user-images.githubusercontent.com/302936/112503511-44d96300-8d8b-11eb-9e52-603118751133.png)\r\n\r\nEven though I am explicitly calling the `plt.close()` function.\r\n\r\nWhen using the `'agg'` backend instead of the `'MacOSX'` backend by uncommenting line 6, I get:\r\n![no_leak](https://user-images.githubusercontent.com/302936/112503746-781bf200-8d8b-11eb-97a6-79f49fb140cc.png)\r\n\r\nWhich I would expect to be the normal behavior.\r\n\r\nAs I have been unable to reproduce this on Linux, I assume that the issue is with the macOS backend.\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: `macOS 11.2.1`\r\n  * Matplotlib version `3.3.4`\r\n  * Matplotlib backend `MacOSX`\r\n  * Python version: `3.7.9`\r\n\r\nI installed Python via `venv` and matplotlib via `pip`.\r\n\r\n\r\nCheers,\r\n\r\nThéotime","author":{"url":"https://github.com/tgrohens","@type":"Person","name":"tgrohens"},"datePublished":"2021-03-25T16:08:15.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":11},"url":"https://github.com/19769/matplotlib/issues/19769"}