On Wed, 1 Jun 2022 at 03:34, Aaron L via Python-ideas <python-ideas@python.org> wrote:
Thanks for your reply.
What's the advantage?
I brought this up thinking about explicitness and readability. Say you want to figure out what this function is doing:
```` def foo() -> t.Iterator[T]: [... 300 lines of code] ```
Is this a generator function? I'd argue that whether it's a generator function or not is fundamental to being able to read it. The type hint alone doesn't tell you whether you're looking at a generator function or not - it might just construct and return an iterator.
Does it actually matter whether it's a generator, or returns some other type of iterable? What's the difference between these two functions: def enumerate_spam(n): yield "spam 1" yield "spam 2" yield "spam 3" yield n yield "the rest of the spam" def enumerate_default_spam(): return enumerate_spam("default") Technically, one of these is a generator, and one is not. But the return value from both of them is a generator object. You can send it values, get values back, all the things you can do with a generator. How fundamental is it that THIS function is a generator, rather than simply that it returns an iterator (or that it returns a generator/coroutine object, etc)? If your function is really just named "foo" and has 300 lines of code, you have other problems. Normally, the function's name should tell you a lot. In your case, you seem to also have a return type hint, which tells you a bit more, so that ought to be sufficient? Maybe that's not sufficient for your codebase. Well, that's what docstrings and decorators and code comments are for :) ChrisA