luhn.py: Favor list comprehensions over maps (#4663)

* luhn.py: Favor list comprehensions over maps

As discussed in CONTRIBUTING.md.

* updating DIRECTORY.md

Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>

Christian Clauss committed 4y ago

46e56fa6f2e473d1300846b2b96e56f498872400

Parent: 5e7eed6

Committed by GitHub <noreply@github.com> on 8/27/2021, 9:45:14 AM