René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"PythonException.Format() throws another PythonException.","articleBody":"### Environment\r\n\r\n-   Pythonnet version: V2.5.1.\r\n-   Python version: V3.8.4 64 bit\r\n-   Operating System: Windows 10 64 bit\r\n\r\n### Details\r\n1. Run the following code in a console application with Visual Studio.\r\n\r\n```csharp\r\nusing (Py.GIL())\r\n{\r\n\r\n    var script = \"a=b\\n\";\r\n    try\r\n    {\r\n        PythonEngine.Exec(script);\r\n    }\r\n    catch (PythonException ex)\r\n    {\r\n        try\r\n        {\r\n            var m = ex.Format();\r\n        }\r\n        catch (Exception exception)\r\n        {\r\n            var t = exception.GetType();\r\n            var s = exception.Message;\r\n        }\r\n    }\r\n}\r\n```\r\n\r\nSince \"a=b\" is invalid, I expected an error message like so returned by `ex.Format()`:\r\n\r\n```\r\nTraceback (most recent call last):\r\n  File \"\u003cstring\u003e\", line 1, in \u003cmodule\u003e\r\nNameError: name 'b' is not defined\r\n```\r\n\r\nHowever, Format() throws another PythonException - \"AttributeError : 'str' object has no attribute '__cause__'\" with the following stack trace - list(TracebackException(\\n', '  File \"C:\\\\Python38\\\\Lib\\\\traceback.py\", line 479, in __init__\\n    if (exc_value and exc_value.__cause__ is not None\\n'] .\r\n\r\n","author":{"url":"https://github.com/tetsushmz","@type":"Person","name":"tetsushmz"},"datePublished":"2020-07-25T15:29:24.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":0},"url":"https://github.com/1190/pythonnet/issues/1190"}