Python [PEP-585](https://peps.python.org/pep-0585/) replaces a number of
`typing` module types with built-in equivalents and `collections.abc`
versions as of Python 3.9, with the aim of eventually removing the
`typing` module versions of these classes altogether. Since the minimum
required version of Python listed in the [Contribution Tools
document](https://github.com/carbon-language/carbon-lang/blob/trunk/docs/project/contribution_tools.md#main-tools)
is 3.9, the type hints in the various python files in the repo can be
updated to this style of type hint without a need for backwards
compatibility.
Feel free to close if this isn't a desired change at this time!
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
In Python 3.x it is not necessary to have `object` inheritance in classes, it may be useful to have `object` inheritance in classes if the code has support for Python 3.x, 2.x, but currently the present code does not contain support for python 2.x.
Co-authored-by: martimartins <martim13artins13@gmail.com>
I'm treating my PR to mypy bazel integration as dead in the water. Abandoning that approach, this seems to work reasonably well as a replacement. It's actually a slightly newer version of mypy too -- the bazel integration was stuck on an old version.
Note I don't think we're losing much: we shouldn't be writing too much python.
I'm seeing if I can upstream thundergolfer/bazel-mypy-integration#43, but we can also point at my fork for the time being.
This should resolve conflicts with mypy treating imports as non-hermetic, creating inconsistent behavior if packages are/aren't installed locally.