Autofill CoventryBS's silly 2FA with Bitwarden regex custom fields.

coventry_regex.py

"""
Take in a CoventryBS grid card as a text file, output regex custom fields for
Bitwarden to autofill your grid card challenge for you.
"""
from __future__ import print_function
import fileinput
import itertools
import sys

COLS = 'ABCDEFGHIJ'
ROWS = range(1, 6)

if __name__ == "__main__":
    numbers = [l.strip().split() for l in fileinput.input()
               if len(l.strip().split()) > 0]
    if len(numbers) != 5 or any(len(n) != 10 for n in numbers):
      print('ERROR: Expected a 5 rows x 10 columns grid of numbers.')
      sys.exit(1)
    by_value = {}
    for (r, c), v in zip(itertools.product(ROWS, COLS), sum(numbers, [])):
        by_value.setdefault(v, []).append('%s%d' % (c, r))
    print("Use these as the keys for your Bitwarden custom fields, "
          "with values 0-9\n")
    for k in sorted(by_value):
        print('regex=^(' + '|'.join(sorted(by_value[k])) + ').*')

    print("\nI found it easiest to copy and paste into the notes and "
          "then copy and paste to create each individual field.")