new_contents: #!/usr/bin/env python3
  
  # this file is linked to unittest testing
  # Python 3 Implementation of the Luhn Algorithm
  # Checks to see if 14, 15 or 16 digit account number is Luhn Compliant.  
  # See https://en.wikipedia.org/wiki/Luhn_algorithm for formula details.  
  # where cardNumber is an account number received as a string:
  
  class aLuhn(object):
      def doLuhn(cardNumber):
          cardLength = str(cardNumber)
          try: 
              cardNumbers = int(cardNumber)
          except ValueError:
              return(False)
          cardLength = len(cardLength)
          everyOtherFromFarRightFor16 = [-2,-4,-6,-8,-10,-12,-14,-16]
          everyOtherFromFarRightFor15 = [-2,-4,-6,-8,-10,-12,-14]
          everyOddFromFarRightButOneFor15 = [-3,-5,-7,-9,-11,-13,-15]
          everyOddFromFarRightButOneFor14 = [-3,-5,-7,-9,-11,-13]
          testNumber = str(cardNumber)
          doubleList = []
          doubleSet = []
          addUpDoubles = 0
          addUpOthers = 0
          if (cardLength == 16):
              doubleList = everyOtherFromFarRightFor16
              addUpTheOddDigits = everyOddFromFarRightButOneFor15
          elif (cardLength == 15):
              doubleList = everyOtherFromFarRightFor15
              addUpTheOddDigits = everyOddFromFarRightButOneFor15
          elif (cardLength == 14):
              doubleList = everyOtherFromFarRightFor15
              addUpTheOddDigits = everyOddFromFarRightButOneFor14
          else:
              return(False)
          for each in doubleList:
              doubleThis = cardNumber[each]
              doubleThis = int(doubleThis) * 2
              nowDoubled = str(doubleThis)
              if (len(nowDoubled) == 1):
                  nowDoubled = nowDoubled
                  doubleSet.append(nowDoubled)
              else:
                  db1, db2 = nowDoubled[0], nowDoubled[1]
                  db1, db2 = int(db1), int(db2)
                  dbladd = db1 + db2
                  doubleSet.append(dbladd)
          for each in doubleSet:
              addUpDoubles += int(each)
          print('addUpDoubles:', addUpDoubles)
          for each in addUpTheOddDigits:
              addOther = cardNumber[each]
              otherToAdd = int(addOther)
              addUpOthers += otherToAdd
          print('addUpOthers:', addUpOthers)
          totalSum = int(addUpDoubles) + int(addUpOthers)
          print('totalSum:', totalSum)
          totalSumTimesNine = (totalSum * 9)
          modTheTotalSum = (totalSumTimesNine % 10)
          if (str(modTheTotalSum) == cardNumber[-1]):
              return(True)
          else:
              return(False)
  
subject: Create luhn.py file