Sourced from mypy's changelog.

Mypy Release Notes

Next Release

Mypy 1.16

We’ve just uploaded mypy 1.16 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.

Different Property Getter and Setter Types

Mypy now supports using different types for a property getter and setter:

class A:
    _value: int
@property
def foo(self) -> int:
    return self._value
@foo.setter

def foo(self, x: str | int) -> None:

try:

self._value = int(x)

except ValueError:

raise Exception(f"'{x}' is not a valid value for 'foo'")

This was contributed by Ivan Levkivskyi (PR 18510).

Flexible Variable Redefinitions (Experimental)

Mypy now allows unannotated variables to be freely redefined with different types when using the experimental --allow-redefinition-new flag. You will also need to enable --local-partial-types. Mypy will now infer a union type when different types are assigned to a variable:

# mypy: allow-redefinition-new, local-partial-types
def f(n: int, b: bool) -> int | str:
if b:
x = n
else:
</tr></table>

... (truncated)

• 9e72e96 Update version to 1.16.0
• 8fe719f Add changelog for 1.16 (#19138)
• 2a036e7 Revert "Infer correct types with overloads of Type[Guard | Is] (#19161)
• b6da4fc Allow enum members to have type objects as values (#19160)
• 334469f [mypyc] Improve documentation of native and non-native classes (#19154)
• a499d9f Document --allow-redefinition-new (#19153)
• 96525a2 Merge commit '9e45dadcf6d8dbab36f83d9df94a706c0b4f9207' into release-1.16
• 9e45dad Clear more data in TypeChecker.reset() instead of asserting (#19087)
• 772cd0c Add --strict-bytes to --strict (#19049)
• 0b65f21 Admit that Final variables are never redefined (#19083)
• Additional commits viewable in compare view

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