wxpython does provide demo,which include demos for most widgets, you could download it from here: https://extras.wxpython.org/wxPython4/extras/4.0.0/

I have been using wxpython on and off for last a few years, the nice thing is it gives a natural looks on each supported OS, so your application won't standout as odd/fancy/weird/off, as with some other cross platform GUI framework do;