Maybe the class-based syntax should be introduced before the functional syntax? It seems to me the class-based syntax is nowadays preferred. I only see the functional syntax recommended when a key is not a valid variable name (e.g., it contains a hyphen or it coincides with a reserved keyword).

Thanks, will make actual edits in a separate PR.

Do we have a general stance on when to usetyping_extensions

I don't think we do. My views:

• 3.7 is close enough to EOL that I don't mind having random snippets in examples assume 3.8. I'm doing a big docs editing pass now, I may as well save us some time in four months (we may still want to support 3.7 for a little longer, but we don't need to target our educational material at those users)
• We should still havetyping_extensions documented in places that it's helpful, it just doesn't necessarily need to be every snippet
• We should also improve the error message mypy gives when imports are missing fromtyping

PR for the suggestion here:#14591