René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Closing figures is done by number","articleBody":"### Closing figures is done by number\r\n\r\n**Currently, closing a figure is done using the `num` attribute in the manager. This can cause problems if there are figures not managed by pyplot, as the number could be the same as a\r\npyplot-managed figure.**\r\n\r\nAs there are efforts to reduce the dependency on pyplot, such as #14024, this should be changed for those to work well. Alternatively, a way to create a manager which selects an appropiate number could work.\r\n\r\n**Code for reproduction**\r\n\r\n```python\r\nimport matplotlib.pyplot as plt \r\n\r\n# Figure managed by pyplot \r\nfig1 = plt.figure() \r\n \r\n# Figure not managed by pyplot, but using the same backend \r\nfig2 = fig = plt.new_figure_manager(1).canvas.figure \r\n\r\nfig1.show() \r\nfig2.show()\r\n```\r\n\r\n**Actual outcome**\r\n\r\nClosing one figure closes both.\r\n\r\n**Expected outcome**\r\n\r\nClosing one figure leaves the other open.\r\n\r\n**Matplotlib version**\r\n  * Operating system: All\r\n  * Matplotlib version: 3.0.3\r\n  * Matplotlib backend (`print(matplotlib.get_backend())`): Qt5Agg\r\n  * Python version: All\r\n\r\n","author":{"url":"https://github.com/vnmabus","@type":"Person","name":"vnmabus"},"datePublished":"2019-09-06T14:06:18.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":4},"url":"https://github.com/15203/matplotlib/issues/15203"}