id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
32971	System check methods can yield their items instead of creating lists at every layer	Chris Jerdonek	nobody	"I noticed that many of the internal ""check()"" methods used by `Field` subclasses return lists (including the empty list) when they can just yield items (or yield nothing). This is because the concrete `check()` implementations unpack the return value when constructing a new list. See here for one example of such a `check()` method: https://github.com/django/django/blob/f331eba6d576752dd79c4b37c41d981daa537fe6/django/db/models/fields/__init__.py#L196-L205

The proposed change, then, would be to change methods like the following to yield their items instead of creating and returning a list: https://github.com/django/django/blob/f331eba6d576752dd79c4b37c41d981daa537fe6/django/db/models/fields/__init__.py#L243-L254

It looks like there are 23 methods in that file with a name starting with `_check...`."	Cleanup/optimization	closed	Core (System checks)	dev	Normal	wontfix			Unreviewed	0	0	0	0	0	0