Environment

• Python.NET version: 3.0.5
• Tested on three configurations:
  • Windows 10, Python 3.12.4, .NET Framework
  • Windows 10, Python 3.12.4, .NET 9.0.201
  • Debian 12, Python 3.11.2, .NET 8.0.407

Details

I have an abstract .NET class, which has abstract methods to override within a netstandard2.0 library. When I try to derive from such a class in Python, it throws a TypeError during class object creation.

Below is a basic example.

.NET library code:

namespace TestLib
{
    public abstract class TestClass
    {
        public string Foo()
        {
            return "Foo";
        }

        protected abstract string Bar();
    }
}

Python code:

from pathlib import Path

import clr

clr.AddReference(str(Path(__file__).parent / 'TestLib.dll'))

from TestLib import TestClass


class SubTestClass(TestClass):
    __namespace__ = 'CrlTest'

    def Bar(self):
        return 'Bar'


if __name__ == '__main__':
    stc = SubTestClass()
    print('Foo() -> ' + stc.Foo())
    print('Bar() -> ' + stc.Bar())

Python script output:

Traceback (most recent call last):
  File "<redacted>\crl_test.py", line 10, in <module>
    class SubTestClass(TestClass):
TypeError: Method 'Bar' in type 'CrlTest.SubTestClass' from assembly 'Python.Runtime.Dynamic, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null' does not have an implementation.