I created https://bugs.python.org/issue36142 which adds a new internal _PyArgv structure to be able to pass command line arguments as bytes (char*) or Unicode (wchar_t*). It’s an helper to factorize the code. My change also rework Python initialization to be able to initialize _PyPreConfig and _PyCoreConfig structures (list of parameters) from command line arguments, whereas previously command line arguments were only handled in main.c (somehow private API).
This PR is a small step towards new Python initialization APIs which would accept command line arguments. (Py_Main() cannot be used to embed Python into an application.)