def get_uuid(app, user):
 try:
  return app.addonpurchase_set.get(user=user).uuid
 except ObjectDoesNotExist:
  return 'none'

def get_uuid ( app , user ) : try : return app . addonpurchase_set . get ( user = user ) . uuid except ObjectDoesNotExist : return 'none'
return a uuid for use in the payment flow .