message: removes characters before the P in the pipette barcode
diff: @@ -76,6 +76,9 @@ def _user_submitted_barcode(max_length):
  barcode = input('BUTTON + SCAN: ').strip()
  if len(barcode) > max_length:
  raise Exception(BAD_BARCODE_MESSAGE.format(barcode))
  + # remove all characters before the letter P
  + # for example, remove ASCII selector code "\x1b(B" on chinese keyboards
  + barcode = barcode[barcode.index('P'):]
  return barcode
  