PySimpleGUI/DemoPrograms/Demo_Script_Parameters.py

#!/usr/bin/env python
import PySimpleGUI as sg
import sys
'''
Quickly add a GUI to your script!

This simple script shows a 1-line-GUI addition to a typical Python command line script.

Previously this script accepted 1 parameter on the command line.  When executed, that
parameter is read into the variable fname.

The 1-line-GUI shows a form that allows the user to browse to find the filename. The GUI
stores the result in the variable fname, just like the command line parsing did.
'''

fname = ''
if len(sys.argv) == 1:
    layout = [
        [sg.Text('Document to open')],
        [sg.Input(), sg.FileBrowse()],
        [sg.CloseButton('Open'), sg.CloseButton('Cancel')]
    ]
    window = sg.Window('My Script', layout)
    event, values = window.read()
    window.close()
    fname = values['-FNAME-']
else:
    fname = sys.argv[1]
if not fname:
    sg.popup("Cancel", "No filename supplied")
    raise SystemExit("Cancelling: no filename supplied")