Python works on multiple platforms and can be used for desktop and web applications, thus I conclude that there is some way to compile it into an executable for Mac, Windows
PySimpleGUI wraps tkinter and works on Python 3 and 2.7. It also runs on Qt, WxPython and in a web browser, using the same source code for all platforms.
You can make custom GUIs that utilize all of the same widgets that you find in tkinter (sliders, checkboxes, radio buttons, ...). The code tends to be very compact and readable.
#!/usr/bin/env python
import sys
if sys.version_info[0] >= 3:
import PySimpleGUI as sg
else:
import PySimpleGUI27 as sg
layout = [[ sg.Text('My Window') ],
[ sg.Button('OK')]]
window = sg.Window('My window').Layout(layout)
button, value = window.Read()
As explained in the PySimpleGUI Documentation, to build the .EXE file you run:
pyinstaller -wF MyGUIProgram.py