31.05.22 16:21, Chris Angelico пише:
On Tue, 31 May 2022 at 23:00, Aaron L via Python-ideas <python-ideas@python.org> wrote:
After getting used to writing async functions, I’ve been wanting use a similar syntax to declare generator functions.
What's the advantage? You can just use normal function syntax to define them, and it works correctly. Do you need the ability to declare that it's a generator even without any yields in it?
The advantage is that you cannot accidentally turn a function into a generator by adding "yield". If the result of the call is ignored (it is expected to be None), this bug can live a long time. It is a common issue: test containing yield always passes. Since 3.11 the unittest module emits a warning if a test method returns not None, but it will not solve all problems: the test can call helpers, and if they are generators, the call is virtually no-op. This error can also occur in non-test code. Asynchronous functions are more reliable. "async" is mandatory, and if you do not await the result of an asynchronous function call you will get a loud warning. I think it is a time to apply the same approach to generator functions.