[hathawsh]

That concept has been formalized as part of the Python standard library.

https://docs.python.org/3/library/doctest.html

[flakes]

Ah very nice! Did not realize this was a part of the standard library!

[lmz]

It's been there since Python v2.1 https://docs.python.org/release/2.1/lib/module-doctest.html

[sakesun]

Here is the first announce of doctest I can find (1999) I think it's Python 1.5 time.

https://groups.google.com/g/comp.lang.python/c/DfzH5Nrt05E/m...