Missed inv(checksum)

[seriyvolk83]

python-stdnum/stdnum/verhoeff.py

Line 113 in dc850d6

return str(_multiplication_table[checksum(str(number) + '0')].index(0))

At the end of the calculation of the new checksum, you need to apply inv(c) function (see https://en.wikipedia.org/wiki/Verhoeff_algorithm )

inv = [0, 4, 3, 2, 1, 5, 6, 7, 8, 9]

Write unit tests please.

Check sum for 0241144346 -> 1

[arthurdejong]

I've added more tests in 051e63f and I'm pretty sure the implementation in python-stdnum is correct.

If I understand correctly you say that 0241144346 should result in a checksum of 1. I'm pretty sure the check digit should be 1, not the check sum:

>>> verhoeff.is_valid('0241144346')
False
>>> verhoeff.checksum('0241144346')
7
>>> verhoeff.calc_check_digit('0241144346')
'1'
>>> verhoeff.checksum('02411443461')
0

If I misunderstood, please clarify.

[seriyvolk83]

Indeed, you right. I just mixed the turns checksum and checkdigit. Thank you!