Are you/your company still using Python 2 in production?

One project I'm involved in. We used a dependency which was Python 2 only. When they finally upgraded to Python 3, it was almost a complete rewrite and completely undocumented, and broke a ton of functionality we used. We didn't have the resource to fix the mess and aren't actively developing it, so we dumped it in a Docker container with the pinned versions, and use it as is.

Also worth saying that a lot of commercial C# applications that bundle a Python console are using Python 2.7, because IronPython doesn't go higher than that currently.

Yup. We are working to phase it out and replace it with better solutions, but it is there and working at scale (about 5 million requests a minute across the cluster, looking at graphs). Killing it slowly as we move load out of it. Pretty sure we've moved out 90% of the load over the last couple of years.

Only one project is still in Python2. A project that were transfered to my without test, docs, etc. and a component heavily relying in sockets, unicode, regex that i'm quite scare to port to python3.

I'll guess I will decouple that component from others and I'll keep it in python3 while porting the rest to python3 in the future.

Do build dependencies count?

I have a build script that requires it (rather, it's a build script of a dependency). I didn't write it and don't have time or incentive to upgrade it, since it works fine.