@echo off
setlocal
cd /d "%~dp0"

where python >nul 2>&1
if %errorlevel% equ 0 (
  set "PY=python"
) else (
  where py >nul 2>&1
  if errorlevel 1 (
    echo Python not found. Install from https://www.python.org/
    pause
    exit /b 1
  )
  set "PY=py"
)

echo Calculator: http://localhost:8888
start "" "http://localhost:8888"
"%PY%" -m http.server 8888 --bind 127.0.0.1

echo.
pause