test_luhn.doctest - more detailed doctests for stdnum.luhn module

Copyright (C) 2010, 2011, 2013 Arthur de Jong

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This file contains more detailed doctests for the stdnum.luhn module. It
tries to test more corner cases and detailed functionality that is not
really useful as module documentation.

>>> from stdnum import luhn


These are normal variations that should just work. Calculating checksums:

>>> luhn.checksum('4992739871')
9
>>> luhn.checksum('490154203237518')
0
>>> luhn.checksum('abcdefe', alphabet='abcdef')
0


The same numbers but now simply ask for validation:

>>> luhn.validate('4992739871')
Traceback (most recent call last):
    ...
InvalidChecksum: ...
>>> luhn.validate('490154203237518')
'490154203237518'
>>> luhn.validate('abcdefe', alphabet='abcdef')
'abcdefe'

Adding a check digit to the numbers so they are all valid:

>>> luhn.calc_check_digit('4992739871')
'6'
>>> luhn.validate('49927398716')
'49927398716'
>>> luhn.calc_check_digit('142857')
'2'
>>> luhn.validate('1428572')
'1428572'
>>> luhn.calc_check_digit('398438246238642378648236487236482734')
'7'
>>> luhn.validate('3984382462386423786482364872364827347')
'3984382462386423786482364872364827347'