Issue 940026: Explain 'in' keyword as it is first used (original) (raw)

Because of a question on a mailing list, I tried to find where the 'in' keyword, for containment testing, was first introduced in the Python tutorial. It turned out not to be, but to be silently introduced in section 4.7.1 (default argument values), and very briefly explained in 5.7 (more on conditions).

This patch adds a (very) brief note at the place where the 'in' keyword is first used for containment testing (4.7.1) explaining what it means.