Introduction to wxPython
Ensure you have a working installation of pip. Then install the required dependencies via
sudo apt install python3-wxgtk4.0
If you are not using a Debian-based Linux, you may instead run
pip install --upgrade --user wxpython
Note that the latter option requires a series of development packages to be present on your system in order to compile the dependencies. The required packages are likely named libwxgtk3.2-dev and libgtk-3-dev.
From now on, you should be able to import wx in your python programs. To get started with GUI programming in Python, follow the official wxPython tutorial