Does Python have a "PYTHONBUFFERED" Environment Variable?

Question

I see many people setting ENV PYTHONBUFFERED=1 in their Dockerfile. Just Google it.

I know that PYTHONUNBUFFERED exists (emphasis on the "UN").

So my basic question is, does PYTHONBUFFERED exist, do a lot of people just misspell it, or is it a concept specific to Docker?

Example seen in a Dockerfile:

FROM --platform=linux/amd64 python:3.10-buster
ENV PYTHONBUFFERED=1
...

Answer 1

While in many cases it's impossible to prove a negative, this isn't one of them.

Searching the CPython source code for PYTHONBUFFERED has no matches. This is, thus, human error.