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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"v3.3.0 breaks sca(ax)","articleBody":"Hi,\r\n\r\nI encountered an error calling sca(ax) together with usage of FigureCanvasTkAgg().  Following would be a simple sequence illustrating the problem.\r\n```\r\n // Note that plt.gca().figure == figure\r\n... = FigureCanvasTkAgg(figure, ...)\r\nplt.sca(plt.gca())\r\n```\r\nThe problem is because FigureCanvasTkAgg(...) will call FigureCanvasBase.__init__(...) which resets the manager field needed in sca().  Below are the listing showing the problem:\r\n```\r\nclass FigureCanvasBase:\r\n    def __init__(self, figure):\r\n        ...\r\n        figure.set_canvas(self)\r\n        self.figure = figure\r\n        **# Here it is setting canvas.manager to None!!**\r\n        self.manager = None\r\n        ...\r\n\r\ndef sca(ax):\r\n    \"\"\"\r\n    Set the current Axes to *ax* and the current Figure to the parent of *ax*.\r\n    \"\"\"\r\n    if not hasattr(ax.figure.canvas, \"manager\"):\r\n        raise ValueError(\"Axes parent figure is not managed by pyplot\")\r\n      **# !!! ax.figure.canvas.manager is None!**\r\n    _pylab_helpers.Gcf.set_active(ax.figure.canvas.manager)\r\n    ax.figure.sca(ax)\r\n```\r\n\r\nFor workaround, I checked out old version of sca(ax) from 3.2.2 and it seems to be working.  On the other hand, I am not sure whether the old version is robust in v3.3.0 despite of this working situation.\r\n```\r\ndef sca(ax):\r\n    \"\"\"\r\n    Set the current Axes instance to *ax*.\r\n\r\n    The current Figure is updated to the parent of *ax*.\r\n    \"\"\"\r\n    managers = _pylab_helpers.Gcf.get_all_fig_managers()\r\n    for m in managers:\r\n        if ax in m.canvas.figure.axes:\r\n            _pylab_helpers.Gcf.set_active(m)\r\n            m.canvas.figure.sca(ax)\r\n            return\r\n    raise ValueError(\"Axes instance argument was not found in a figure\")\r\n```\r\nPlease check and see whether bring back of old version of sca(ax) is a correct fix of this issue.\r\n","author":{"url":"https://github.com/david-c-wong","@type":"Person","name":"david-c-wong"},"datePublished":"2021-01-27T21:55:38.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":11},"url":"https://github.com/19380/matplotlib/issues/19380"}