@echo off
cd /d "%~dp0"

where python >nul 2>&1
if %ERRORLEVEL%==0 (
  python gui_app.py
  goto :done
)

where py >nul 2>&1
if %ERRORLEVEL%==0 (
  py -3 gui_app.py
  goto :done
)

echo [error] Python 3 не найден. Установите с https://www.python.org/downloads/
pause
exit /b 1

:done
pause