Migrate Python 2 → 3

Python 2 has been EOL since January 2020. If you still have Py2 code, it's because legacy environment locks (regulated, government, embedded) prevent upgrade — or because the code base is large enough that nobody wanted to bite the bullet. This skill is the bullet.

When to use

• Stuck on Python 2.7 and finally given approval to upgrade.
• Forking a Py2-only library to make it 3-compatible.
• Dual-stack (2 and 3) codebase being collapsed to 3-only.

When NOT to use

• New code — should be Python 3 from day 1.
• Already on Python 3.x — see python-version-upgrade (different skill, not in this repo yet).
• Using libraries that are truly Py2-only — fork or replace, not convert.

The honest cost