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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Can not call method in parent class, when using nested classes with inheritance","articleBody":"### Environment\r\n\r\nPythonnet version: 2.5.1\r\nPython version: Python 3.9.2\r\nOperating System: MacOS\r\n.NET Runtime: 5.0.200\r\n\r\n### Details\r\n\r\nRelated to the problem reported in #1414 \r\n\r\nI.e. classes-in-classes are not handled properly in Pythonnet.\r\n\r\nEven when applying the workaround mentioned in the #1414 issue there are still problems related to the inheritance.\r\n\r\nNamely, I can not call a method declared on the baseclass, on an instance of the nested child class.\r\n\r\nThe following code demonstrates the issue\r\n\r\n```cs\r\n\r\nnamespace pythonnet_testing {\r\n\r\n  public class Bar {\r\n\r\n    public string MethodInBaseClass() {\r\n      return \"hello\";\r\n    }\r\n\r\n    public class Hej : Bar {\r\n    }\r\n  }\r\n\r\n  public class Foo {\r\n    public Bar Bar;\r\n\r\n    public static Foo Create() {\r\n      Foo f = new();\r\n      f.Bar = new Bar.Hej();\r\n      return f;\r\n    }\r\n  }\r\n\r\n  class Program {\r\n    static void Main(string[] args) {\r\n\r\n      var pyCode = @\"\r\nimport pythonnet_testing\r\nf = pythonnet_testing.Foo.Create()\r\nprint('Trying to access member of nested subclass')\r\n_ = pythonnet_testing.Bar # NOTE: The python code crashes unless this explicit reference to the Bar class is used\r\nprint(f'Bar: {f.Bar}')\r\nprint(f'Method call: {f.Bar.MethodInBaseClass()}')\r\n\r\n      \";\r\n\r\n      PythonEngine.Initialize();\r\n\r\n      using (Py.GIL()) {\r\n        PythonEngine.Exec(pyCode);\r\n      }\r\n    }\r\n  }\r\n```\r\n\r\nRunning this gives the following error message\r\n\r\n```\r\nTrying to access member of nested subclass\r\nBar: pythonnet_testing.Bar+Hej\r\nUnhandled exception. Python.Runtime.PythonException: AttributeError : 'Hej' object has no attribute 'MethodInBaseClass'\r\n['  File \"\u003cstring\u003e\", line 7, in \u003cmodule\u003e\\n']   at Python.Runtime.PythonException.ThrowIfIsNull(BorrowedReference reference)\r\n   at Python.Runtime.PythonEngine.RunString(String code, Nullable`1 globals, Nullable`1 locals, RunFlagType flag)\r\n```\r\n\r\nIn order to call the `MethodInBaseClass` method on the child class, I must explicitly re-define it like this:\r\n\r\n```cs\r\n    public class Hej : Bar {\r\n      public new string MethodInBaseClass() =\u003e base.MethodInBaseClass();\r\n    }\r\n```\r\n\r\n","author":{"url":"https://github.com/koliyo","@type":"Person","name":"koliyo"},"datePublished":"2021-03-18T15:28:28.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/1420/pythonnet/issues/1420"}