On Thu, Jul 2, 2020, 11:08 AM Piper Thunstrom
Paul, this is actually a good question to ask. In general, singular "they" is becoming more popular. It's already used frequently for the singular indeterminate pronoun:
The first attested use of singular they in English was in 1375 CE. I'm not sure what time frame Piper uses as the increment for "becoming more popular", but its use has waxed and waned for 650 years.
The usage has never been rare during those 650 years, but neither has it ever been predominant. It is a completely reasonable approach, and I would not object to encouraging it in Python documentation.
Earlier in my life (30-40 years ago) I tended to use s/he or similar forms. I think that 'they' is more inclusive of gender non-binary people, as well as being much more historically established.