import os
import subprocess
import time

gitbash = r"C:\Program Files\Git\git-bash.exe"   # Eventuell anpassen!
backupscript = r"D:\stickbackup2.bash"           # Eventuell anpassen!

while True:
    # Check if stick is present
    if os.path.exists(backupscript):
        print("Stick present")
        # Backup starten
        print("Starte backup...")
        cmd = [gitbash, backupscript]
        subprocess.call(cmd)
        time.sleep(30*60)  # Halbe Stunde
    else:
        print("nix da!")
    time.sleep(10)