double lohn barcode in python

double_luhn.py

# output: 
# 100000000 -> A10000000086
# 100000001 -> A10000000164
# 100000002 -> A10000000242
# 100000003 -> A10000000320
# 100000004 -> A10000000407
# 100000005 -> A10000000575

def luhn_checksum(number):
  total=0
  digits = list(map(int,str(number)))
  reversedDigits = digits[::-1]
  total = 0
  for position, digit in enumerate(reversedDigits):
    if (position + 1) % 2 == 1:
       digit *= 2
       if digit > 9: digit -= 9
    total += digit
  total = total * 9
  return str(total % 10)


for x in range(6):
    value = 100000000 + x
    newValue = "A" + str(value) + str(luhn_checksum(value)) + str(luhn_checksum(value + 1))
    print(" " + str(value) + " -> " + newValue)