Your question here is based on a misunderstanding in the other topic I guess. Where I replied since then
To reply your questions here:
You can run Linux containers on Linux and Windows containers on Windows. Docker Desktop let’s you create a Linux virtual machine to run Linux containers inside that VM. It doesn’t matter where you develop, but you have to make sure your code works on the chosen platform. If you never tried a code on Linux, only on Windows, the problem could be the incompatibility of your app. You need a Python developer to tell you if a Python code or library is supported correctly on another platform
Sometimes your code doesn’t work in a Linux container even if it works on a Linux host, since a container is an isolated system with limited rights for security reasons, and in many cases, you need to develop your app differently to be able to run it in containers, so yes, it is best if you test it in containers from the beginning even during development, but your physical host doesn’t have to be Linux if you are using a Linux virtual machine like the one provided by Docker Desktop.
Of course you can still have problems when you edit a file in a file editor that saves Windows-compatible line endings which is not compatible with Linux. So when you develop for Linux, using LF instead or CRLF is better. LF is usually understood by interpreters on Windows too and by code editors.