Thank you Robin. Running pip with "--no-deps" worked fine, and I was able to install wxPython 4.0.6 on Python 3.4.4.
As for pyinstaller:
I'm still building my app (as an all-inclusive executable file) on Windows 7 32-bit, to achieve the widest audience for my application.
An executable built with Python 3.7.3 crashes on Win7 showing ucrtbase.DLL as the source of the problem.
On Win10 it won't even show me any message...
If you also build on Win7, I'd appreciate if you can share how you successfully use pyinstaller with Python 3.5 (and beyond).
As much as I tried, I couldn't understand the instructions on pyinstaller's site on how to include the required new MSVC libraries.