René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"AttributeError: 'Figure' object has no attribute '_cachedRenderer'","articleBody":"### Bug report\r\n\r\n**Bug summary**\r\n\r\nI was trying to follow the first suggestion of [this post](https://stackoverflow.com/a/45812071/5472354), and copy a figure using pickle. In my example however, this results in an `AttributeError: 'Figure' object has no attribute '_cachedRenderer'`. \r\n\r\n**Code for reproduction**\r\n\r\n```python\r\nimport io\r\nimport pickle\r\nimport numpy as np\r\nfrom copy import copy, deepcopy\r\nfrom contextlib import contextmanager\r\nimport matplotlib.pyplot as plt\r\n\r\n\r\n@contextmanager\r\ndef copy_figure(fig: plt.Figure):\r\n    buf = io.BytesIO()\r\n    pickle.dump(fig, buf)\r\n    buf.seek(0)\r\n    fig_copy = pickle.load(buf)\r\n    # fig_copy = copy(fig)  # you get the same error when using copy instead\r\n    # fig_copy = deepcopy(fig)  # this results in an \"NotImplementedError: \r\n    #    TransformNode instances can not be copied. Consider using frozen() \r\n    #    instead.\" which I have no idea what that means either.\r\n    yield fig_copy\r\n    plt.close(fig_copy)\r\n\r\n\r\ndef example():\r\n    image = np.random.uniform(0, 1, (100, 100))\r\n    fig, ax = plt.subplots()\r\n    image_artist = ax.imshow(image)\r\n    fig.colorbar(image_artist)\r\n    with copy_figure(fig) as copy_fig:\r\n        copy_fig.show()\r\n\r\n    fig.show()\r\n\r\n\r\nexample()\r\n```\r\nI am not sure if this is wanted behaviour, and why this even happens, but if it is not supposed to happen, I guess it would be a simple fix to change this line in `tight_layout.get_renderer`\r\n\r\n```\r\n    if fig._cachedRenderer:\r\n```\r\n\r\nto this line:\r\n\r\n```\r\n    if hasattr(fig, '_cachedRenderer') and fig._cachedRenderer:\r\n```\r\n\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 Home 64bit\r\n  * Matplotlib version: 3.1.3 (via Anaconda)\r\n  * Matplotlib backend: backend_interagg\r\n  * Python version: 3.7.7\r\n\r\n","author":{"url":"https://github.com/mapfiable","@type":"Person","name":"mapfiable"},"datePublished":"2020-06-13T11:03:16.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":2},"url":"https://github.com/17627/matplotlib/issues/17627"}