stdnum.verhoeff

The Verhoeff algorithm.

The Verhoeff algorithm uses two tables for permutations and multiplications to calculate a checksum.

>>> validate('1234')
Traceback (most recent call last):
    ...
InvalidChecksum: ...
>>> checksum('1234')
1
>>> calc_check_digit('1234')
'0'
>>> validate('12340')
'12340'
Traceback (most recent call last):
    ...
InvalidChecksum: ...

stdnum.verhoeff.calc_check_digit(number)

With the provided number, calculate the extra digit that should be appended to make it pass the Verhoeff checksum.

stdnum.verhoeff.checksum(number)

Calculate the Verhoeff checksum over the provided number. The checksum is returned as an int. Valid numbers should have a checksum of 0.

stdnum.verhoeff.is_valid(number)

Checks to see if the number provided passes the Verhoeff checksum.

stdnum.verhoeff.validate(number)

Checks to see if the number provided passes the Verhoeff checksum.