Super compressed version of Luhn's Algorithm in python

LuhnsAlgorithm-Full.py

def luhnsChecksum(cardNumber):
	#returns the actual digits in a string
	def digitsOf(n):
	  return [int(d) for d in str(n) if d.isdigit()]

	#get digits in card number
	digits = digitsOf(cardNumber)

	#get odd digits by incrementing backwards by -2 to -1
	oddDigits = digits[-1::-2]

	#get even digits by incrementing backwards by -2 to -2
	evenDigits = digits[-2::-2]

	#add all the digits together for a checksum
	checksum = sum(oddDigits)

	for d in evenDigits:
		#for every number in the even digits, add the sum of 2x the digit to the checksum
		checksum += sum(digitsOf(d * 2))

	#check whether or not it's evenly divisible by 10 and return whether it is or not
	return checksum % 10 == 0

if __name__ == "__main__":
	#get the card number from user input
	cardNumber = raw_input("Card number: ")
	
	isValid = luhnsChecksum(cardNumber)
	if isValid:
		print "Valid"
	else:
		print "Invalid"

LuhnsAlgorithm.py

def luhnChecksum(cardNumber):
	getDigits = lambda n: [int(d) for d in str(n) if d.isdigit()]
	digits = getDigits(cardNumber)
	oddDigits, evenDigits = digits[-1::-2], digits[-2::-2]
	checksum = sum(oddDigits)
	for d in evenDigits: checksum += sum(getDigits(d * 2))
	return checksum % 10 == 0
if __name__ == "__main__": print "Valid" if luhnChecksum(raw_input("Card number: ")) else "Invalid"