Everything you can do in Python, you can do in C++. Some things are clumsier in C++. For instance, a few classes (like Actor and DirectButton) only exist in Python, but these Python classes are just convenience wrappers around the actual C++ implementation (like Character and PGButton) which you can use instead, just with a bit more effort.
Of course, you could argue that everything is clumsier in C++, so this shouldn’t be a real impediment. But I’d hate to start a language war.