René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Qt Embedding w/ Spyder","articleBody":"I have found a solution to a bug when using the script on:\r\nhttps://matplotlib.org/gallery/user_interfaces/embedding_in_qt_sgskip.html\r\nwith the Spyder IDE (v3.3.2)\r\n\r\nIf the script is run as presented, two issues are present:\r\nIssue 1: The qapp.exec_() does not terminate when the window is closed.\r\n\r\nThis was resolved for me by adding:\r\n`QtWidgets.QApplication.setQuitOnLastWindowClosed(True)`\r\nbefore qapp.exec_() is called:\r\n\r\n```\r\nif not QtWidgets.QApplication.instance():\r\n    qapp = QtWidgets.QApplication(sys.argv)\r\nelse:\r\n    qapp = QtWidgets.QApplication.instance()\r\nQtWidgets.QApplication.setQuitOnLastWindowClosed(True)\r\n\r\napp = ApplicationWindow()\r\napp.show()\r\nqapp.exec_()\r\n```\r\n\r\nIssue 2: When this script is called multiple times in the IPython console, the Kernel dies and must be restarted. Per the comment thread on issue #4349, this is solved by replacing:\r\n\r\n`qapp = QtWidgets.QApplication(sys.argv)`\r\n\r\nwith\r\n```\r\nif not QtWidgets.QApplication.instance():\r\n    qapp = QtWidgets.QApplication(sys.argv)\r\nelse:\r\n    qapp = QtWidgets.QApplication.instance()\r\n```\r\n\r\nCan this be added to the example script?\r\n\r\n**Matplotlib version**\r\n  * Operating system: Windows 10\r\n  * Matplotlib version: 3.0.2\r\n  * Python version: 3.7\r\n\r\n","author":{"url":"https://github.com/gigo318","@type":"Person","name":"gigo318"},"datePublished":"2019-02-10T19:12:21.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":15},"url":"https://github.com/13400/matplotlib/issues/13400"}