A common UI element that you used to see a lot of was the Splash Screen. A splash screen is just a dialog with a logo or art on it that sometimes includes a message about how far along the application has loaded. Some developers use splash screens as a way to tell the user that the application is loading so they don’t try to open it multiple times.
wxPython has support for creating splash screens. In versions of wxPython prior to version 4, you could find the splash screen widget in wx.SplashScreen. However, in wxPython’s latest version, it has been moved to wx.adv.SplashScreen.