Old Python projects rot in a quiet way. Functions get new parameters and the docstring above them stays frozen. I've been building a command-line tool, Legacy Doc-AI, that finds those gaps and drafts fixes. To see if the problem is real, I pointed its scanner at four well-known libraries.
Functions with no docstring at all:
These are raw counts. The scanner counts every function and method it finds, including private helpers and tests, and many of those are fine without docs. So read them as "how much is uncovered", not "how badly these projects are run".
It's early. I'm not claiming it writes perfect docs, and I haven't measured how accurate the drafts are. I want honest feedback from people who maintain older Python code.
There's a free audit: send me a public repo and I'll send back the coverage report. Sign-up is at https://legacy-doc-ai.pages.dev. The planned price is £39 per repo per month. Does that sound sensible? And what would make you trust generated docstrings in your repo?