How to use C++ DLLs in C# UWP Projects?

The first suggestion is to wrap that C++ logic using a WinRT component. Then you can reference this component in UWP application by following steps: adding it to the project, open the files' properties in the Solution Explorer window, and mark them as content to be included in the app package.

If you want to PInvoke the dll, you can follow these steps,

1. Add win32 dll into your UWP project making sure to set its type as 'content'

2. Then in the proper cs file, using DllImport to PInvoke the dll.

You need to make sure your Python dll is not using prohibited APIs in WinRT. You can check this by using /ZW compile option for the dll.