Relax the Python version check for __class_getitem__ tests

[layday]

Description

__class_getitem__ to support generics was introduced in Python 3.7.
In 3.9 some built-ins were made generic but the functionality
for user-defined classes has been there since 3.7.

Checklist

This pull request is:

• A documentation / typographical error fix
  • Good to go, no issue or tests are needed
• A short code fix
  • please include the issue number, and create an issue if none exists, which
    must include a complete example of the issue. one line code fixes without an
    issue and demonstration will not be accepted.
  • Please include: Fixes: #<issue number> in the commit message
  • please include tests. one line code fixes without tests will not be accepted.
• A new feature implementation
  • please include the issue number, and create an issue if none exists, which must
    include a complete example of how the feature would look.
  • Please include: Fixes: #<issue number> in the commit message
  • please include tests.

Have a nice day!

[zzzeek]

hi -

this is basically because we implemented #6804 #6759 is that accurate?

[layday]

Classes can be made "generic" using __class_getitem__ from Python 3.7 onwards. Some classes, like the built-in dict or queue.Queue in the stdlib, were generic in the typeshed but not at runtime (or not at all in the case of dict), i.e. you could subscript them in if TYPE_CHECKING: ... blocks only, prior to Python 3.9. The ability to make them generic was there, but they weren't made generic until 3.9, presumably due to inertia.

[zzzeek]

yes i know all that. confirming this change ideally should have been made when we in fact added __class_getitem__ in c03b6e0 . prior to that change, this test change would fail.

also i thought i just added this to gerrit and it's not there, OK

[sqla-tester]

OK, this is sqla-tester setting up my work on behalf of zzzeek to try to get revision 7bd16d4 of this pull request into gerrit so we can run tests and reviews and stuff

[sqla-tester]

New Gerrit review created for change 7bd16d4: https://gerrit.sqlalchemy.org/c/sqlalchemy/sqlalchemy/+/3089

[zzzeek]

i wonder why we pinned c03b6e0 at 3.9

[layday]

yes i know all that.

Well, I haven't got any other insight 😛

[sqla-tester]

Gerrit review https://gerrit.sqlalchemy.org/c/sqlalchemy/sqlalchemy/+/3089 has been merged. Congratulations! :)