Sourced from mypy's changelog.

Mypy Release Notes

Next Release

Mypy 1.17

We’ve just uploaded mypy 1.17 to the Python Package Index (PyPI). Mypy is a static type checker for Python. This release includes new features and bug fixes. You can install it as follows:

python3 -m pip install -U mypy

You can read the full documentation for this release on Read the Docs.

Optionally Check That Match Is Exhaustive

Mypy can now optionally generate an error if a match statement does not match exhaustively, without having to use assert_never(...). Enable this by using --enable-error-code exhaustive-match.

Example:

# mypy: enable-error-code=exhaustive-match
import enum
class Color(enum.Enum):
RED = 1
BLUE = 2
def show_color(val: Color) -> None:
# error: Unhandled case for values of type "Literal[Color.BLUE]"
match val:
case Color.RED:
print("red")

This feature was contributed by Donal Burns (PR 19144).

Further Improvements to Attribute Resolution

This release includes additional improvements to how attribute types and kinds are resolved. These fix many bugs and overall improve consistency.

• Handle corner case: protocol/class variable/descriptor (Ivan Levkivskyi, PR 19277)
• Fix a few inconsistencies in protocol/type object interactions (Ivan Levkivskyi, PR 19267)
• Refactor/unify access to static attributes (Ivan Levkivskyi, PR 19254)
• Remove inconsistencies in operator handling (Ivan Levkivskyi, PR 19250)
• Make protocol subtyping more consistent (Ivan Levkivskyi, PR 18943)

... (truncated)

• 0260991 Update version string
• 3901aa2 Updates to 1.17 changelog (#19436)
• 7d13396 Initial changelog for 1.17 release (#19427)
• a182dec Combine the revealed types of multiple iteration steps in a more robust manne...
• ab4fd57 Improve the handling of "iteration dependent" errors and notes in finally cla...
• 09ba1f6 [mypyc] Fix exception swallowing in async try/finally blocks with await (#19353)
• 5c65e33 [mypyc] Fix AttributeError in async try/finally with mixed return paths (#19361)
• 934ec50 Lessen dmypy suggest path limitations for Windows machines (#19337)
• a4801f9 Type ignore comments erroneously marked as unused by dmypy (#15043)
• c3bfa0d Handle corner case: protocol vs classvar vs descriptor (#19277)
• Additional commits viewable in compare view

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