Python implementation of the VocaLink UK Bank Account Modulus Checking logic as of the VocaLink 3.10 spec.
pip install ukmodulus
from ukmodulus import validate_number
validate_number('089999', '66374958')
Doesn't currently deal with account numbers which are not 8 digits long. (i.e. doesn't implement the exceptions listed in 4.2 of the VocaLink spec).