Luhn Algorithm as list comprehension

def luhn(card, toCodePoint = None, toIter = None, base = 10):
    toCodePoint = toCodePoint if toCodePoint is not None else lambda x: int(x, base)
    try:
        offset = 1 + len(card) % 2
        cn = enumerate((toCodePoint(x) for x in card), offset)
        return sum(sum(divmod(n * (1 + c % 2), base)) for c, n in cn) % base
    except TypeError:
    	toIter = toIter if toIter is not None else lambda x: str(x)
        luhn(toIter(card), toCodePoint, toIter, base)

def luhnValid(card, toCodePoint = None, toIter = None, base = 10):
	return luhn(card) == 0

def luhnCheckDigit(card, toCodePoint = None, toIter = None, base = 10):
	return (10 - luhn(card)) % 10
         
luhntestnumbers = (
	'378282246310005',  # amex1
    '371449635398431',  # amex2
    '378734493671000',  # amex corporate
    '6011111111111117', # discover1
    '6011000990139424', # discover2
    '5555555555554444', # mc1
    '5105105105105100', # mc2
    '4111111111111111', # visa1
    '4012888888881881', # visa2
    '4222222222222',    # visa3         
)

if __name__ == '__main__':
    for x in luhntestnumbers:
        #assert isvalid(x) == True
        print luhnValid(x), x

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