diff --git a/CHANGELOG.md b/CHANGELOG.md index 66b7cea86fb5..243d46946326 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -12,64 +12,121 @@ We’ve just uploaded mypy 1.10 to the Python Package Index ([PyPI](https://pypi You can read the full documentation for this release on [Read the Docs](http://mypy.readthedocs.io). -**TODO** -- Implement TypeIs (PEP 742) (Jelle Zijlstra, PR [16898](https://github.com/python/mypy/pull/16898)) -- Error handling for recursive TypeVar defaults (PEP 696) (Marc Mueller, PR [16925](https://github.com/python/mypy/pull/16925)) -- Add basic support for recursive TypeVar defaults (PEP 696) (Marc Mueller, PR [16878](https://github.com/python/mypy/pull/16878)) +#### Support TypeIs (PEP 742) -#### Other Notable Changes and Fixes -- fix: incorrect returned type of access descriptors on unions of types (Matthieu Devlin, PR [16604](https://github.com/python/mypy/pull/16604)) -- Fix crash when expanding invalid Unpack in a `Callable` alias (Ali Hamdan, PR [17028](https://github.com/python/mypy/pull/17028)) -- Fix string formatting for string enums (roberfi, PR [16555](https://github.com/python/mypy/pull/16555)) -- Narrow individual items when matching a tuple to a sequence pattern (Loïc Simon, PR [16905](https://github.com/python/mypy/pull/16905)) -- Add TypeGuard and TypeIs traversing in TypeTraverserVisitor (Evgeniy Slobodkin, PR [17071](https://github.com/python/mypy/pull/17071)) -- Improve error message for bound typevar in TypeAliasType (Ali Hamdan, PR [17053](https://github.com/python/mypy/pull/17053)) -- Fix TypedDict init from Type with optional keys (Marc Mueller, PR [17068](https://github.com/python/mypy/pull/17068)) -- Improve yield from inference for unions of generators (Shantanu, PR [16717](https://github.com/python/mypy/pull/16717)) -- Support `TypeAliasType` in a class scope (Ali Hamdan, PR [17038](https://github.com/python/mypy/pull/17038)) -- attrs: Fix emulating hash method logic (Hashem, PR [17016](https://github.com/python/mypy/pull/17016)) -- Use lower-case generics more consistently in error messages (Jukka Lehtosalo, PR [17035](https://github.com/python/mypy/pull/17035)) -- Revert "Revert use of `ParamSpec` for `functools.wraps`" (Tamir Duberstein, PR [16942](https://github.com/python/mypy/pull/16942)) -- Support `TypeAliasType` (Ali Hamdan, PR [16926](https://github.com/python/mypy/pull/16926)) -- Fix type narrowing for types.EllipsisType (Shantanu, PR [17003](https://github.com/python/mypy/pull/17003)) -- Disallow all super calls to methods with trivial bodies (Shantanu, PR [16756](https://github.com/python/mypy/pull/16756)) -- Fix single item enum match type exhaustion (Oskari Lehto, PR [16966](https://github.com/python/mypy/pull/16966)) -- Fix inference with UninhabitedType (Marc Mueller, PR [16994](https://github.com/python/mypy/pull/16994)) -- Allow TypedDict initialization from Type (Marc Mueller, PR [16963](https://github.com/python/mypy/pull/16963)) -- Fix override checking for decorated property (Shantanu, PR [16856](https://github.com/python/mypy/pull/16856)) -- Fix duplicate word in protocols.rst (hesam, PR [16950](https://github.com/python/mypy/pull/16950)) -- Workaround parenthesised context manager issue (Shantanu, PR [16949](https://github.com/python/mypy/pull/16949)) -- Fix narrowing on match with function subject (Edward Paget, PR [16503](https://github.com/python/mypy/pull/16503)) -- Allow inferring +int to be a Literal (Spencer Brown, PR [16910](https://github.com/python/mypy/pull/16910)) +Mypy now supports `TypeIs` ([PEP 742](https://peps.python.org/pep-0742/)), which allows +functions to narrow the type of a value, similar to `isinstance()`. Unlike `TypeGuard`, +`TypeIs` can narrow in both the `if` and `else` branches of an if statement: -#### Stubgen Improvements -- stubgen: Preserve empty tuple annotation (Ali Hamdan, PR [16907](https://github.com/python/mypy/pull/16907)) -- stubgen: Add support for PEP 570 positional-only parameters (Ali Hamdan, PR [16904](https://github.com/python/mypy/pull/16904)) -- stubgen: Replace obsolete typing aliases with builtin containers (Ali Hamdan, PR [16780](https://github.com/python/mypy/pull/16780)) -- stubgen: Fix generated dataclass `__init__` signature (Ali Hamdan, PR [16906](https://github.com/python/mypy/pull/16906)) +```python +from typing_extensions import TypeIs -#### Stubtest Improvements -- stubtest: correct type annotations in _Arguments (Sam Xifaras, PR [16897](https://github.com/python/mypy/pull/16897)) +def is_str(s: object) -> TypeIs[str]: + return isinstance(s, str) + +def f(o: str | int) -> None: + if is_str(o): + # Type of o is 'str' + ... + else: + # Type of o is 'int' + ... +``` + +`TypeIs` will be added to the `typing` module in Python 3.13, but it +can be used on earlier Python versions by importing it from +`typing_extensions`. + +This feature was contributed by Jelle Zijlstra (PR [16898](https://github.com/python/mypy/pull/16898)). + +#### Support TypeVar Defaults (PEP 696) + +[PEP 696](https://peps.python.org/pep-0696/) adds support for type parameter defaults. +Example: + +```python +from typing import Generic +from typing_extensions import TypeVar + +T = TypeVar("T", default=int) + +class C(Generic[T]): + ... + +x: C = ... +y: C[str] = ... +reveal_type(x) # C[int], because of the default +reveal_type(y) # C[str] +``` + +TypeVar defaults will be added to the `typing` module in Python 3.13, but they +can be used with earlier Python releases by importing `TypeVar` from +`typing_extensions`. + +This feature was contributed by Marc Mueller (PR [16878](https://github.com/python/mypy/pull/16878) +and PR [16925](https://github.com/python/mypy/pull/16925)). + +#### Detect Additional Unsafe Uses of super() + +Mypy will reject unsafe uses of `super()` more consistently, when the target has a +trivial (empty) body. Example: + +```python +class Proto(Protocol): + def method(self) -> int: ... + +class Sub(Proto): + def method(self) -> int: + return super().meth() # Error (unsafe) +``` + +This feature was contributed by Shantanu (PR [16756](https://github.com/python/mypy/pull/16756)). + +#### Stubgen Improvements +- Preserve empty tuple annotation (Ali Hamdan, PR [16907](https://github.com/python/mypy/pull/16907)) +- Add support for PEP 570 positional-only parameters (Ali Hamdan, PR [16904](https://github.com/python/mypy/pull/16904)) +- Replace obsolete typing aliases with builtin containers (Ali Hamdan, PR [16780](https://github.com/python/mypy/pull/16780)) +- Fix generated dataclass `__init__` signature (Ali Hamdan, PR [16906](https://github.com/python/mypy/pull/16906)) #### Mypyc Improvements -- [mypyc] Refactor: add two list primitive ops (Jukka Lehtosalo, PR [17058](https://github.com/python/mypy/pull/17058)) -- [mypyc] Refactor: use primitive op for initializing list item (Jukka Lehtosalo, PR [17056](https://github.com/python/mypy/pull/17056)) -- [mypyc] Refactor: move tagged int related code to mypyc.lower.int_ops (Jukka Lehtosalo, PR [17052](https://github.com/python/mypy/pull/17052)) -- [mypyc] Implement lowering for remaining tagged integer comparisons (Jukka Lehtosalo, PR [17040](https://github.com/python/mypy/pull/17040)) -- [mypyc] Implement lowering pass and add primitives for int (in)equality (Jukka Lehtosalo, PR [17027](https://github.com/python/mypy/pull/17027)) -- [mypyc] Optimize away some bool/bit registers (Jukka Lehtosalo, PR [17022](https://github.com/python/mypy/pull/17022)) -- [mypyc] Provide an easier way to define IR-to-IR transforms (Jukka Lehtosalo, PR [16998](https://github.com/python/mypy/pull/16998)) -- [mypyc] Remangle redefined names produced by async with (Richard Si, PR [16408](https://github.com/python/mypy/pull/16408)) -- [mypyc] Optimize TYPE_CHECKING to False at Runtime (Srinivas Lade, PR [16263](https://github.com/python/mypy/pull/16263)) -- [mypyc] Fix compilation of unreachable comprehensions (Richard Si, PR [15721](https://github.com/python/mypy/pull/15721)) -- [mypyc] Don't crash on non-inlinable final local reads (Richard Si, PR [15719](https://github.com/python/mypy/pull/15719)) + +- Provide an easier way to define IR-to-IR transforms (Jukka Lehtosalo, PR [16998](https://github.com/python/mypy/pull/16998)) +- Implement lowering pass and add primitives for int (in)equality (Jukka Lehtosalo, PR [17027](https://github.com/python/mypy/pull/17027)) +- Implement lowering for remaining tagged integer comparisons (Jukka Lehtosalo, PR [17040](https://github.com/python/mypy/pull/17040)) +- Optimize away some bool/bit registers (Jukka Lehtosalo, PR [17022](https://github.com/python/mypy/pull/17022)) +- Remangle redefined names produced by async with (Richard Si, PR [16408](https://github.com/python/mypy/pull/16408)) +- Optimize TYPE_CHECKING to False at Runtime (Srinivas Lade, PR [16263](https://github.com/python/mypy/pull/16263)) +- Fix compilation of unreachable comprehensions (Richard Si, PR [15721](https://github.com/python/mypy/pull/15721)) +- Don't crash on non-inlinable final local reads (Richard Si, PR [15719](https://github.com/python/mypy/pull/15719)) +- Support `TypeAliasType` (Ali Hamdan, PR [16926](https://github.com/python/mypy/pull/16926)) #### Documentation Improvements -- Update running_mypy.rst add closing bracket (Roman Solomatin, PR [17046](https://github.com/python/mypy/pull/17046)) -- Docs: docstrings in checker.py, ast_helpers.py (Ihor, PR [16908](https://github.com/python/mypy/pull/16908)) -- docs: Add missing ClassVar import (youkaichao, PR [16962](https://github.com/python/mypy/pull/16962)) -- Docs: Update `TypedDict` import statements (Riccardo Di Maio, PR [16958](https://github.com/python/mypy/pull/16958)) -- Docs: adding missing `mutable-override` to section title (James Braza, PR [16886](https://github.com/python/mypy/pull/16886)) +- Import `TypedDict` from `typing` instead of `typing_extensions` (Riccardo Di Maio, PR [16958](https://github.com/python/mypy/pull/16958)) +- Add missing `mutable-override` to section title (James Braza, PR [16886](https://github.com/python/mypy/pull/16886)) + +#### Error Reporting Improvements + +- Improve error message for bound TypeVar in TypeAliasType (Ali Hamdan, PR [17053](https://github.com/python/mypy/pull/17053)) +- Use lower-case generics more consistently in error messages (Jukka Lehtosalo, PR [17035](https://github.com/python/mypy/pull/17035)) + +#### Other Notable Changes and Fixes +- Fix incorrect inferred type when accessing descriptor on union type (Matthieu Devlin, PR [16604](https://github.com/python/mypy/pull/16604)) +- Fix crash when expanding invalid `Unpack` in a `Callable` alias (Ali Hamdan, PR [17028](https://github.com/python/mypy/pull/17028)) +- Fix false positive when string formatting with string enum (roberfi, PR [16555](https://github.com/python/mypy/pull/16555)) +- Narrow individual items when matching a tuple to a sequence pattern (Loïc Simon, PR [16905](https://github.com/python/mypy/pull/16905)) +- Fix false positive from type variable within TypeGuard or TypeIs (Evgeniy Slobodkin, PR [17071](https://github.com/python/mypy/pull/17071)) +- Improve `yield from` inference for unions of generators (Shantanu, PR [16717](https://github.com/python/mypy/pull/16717)) +- Support `TypeAliasType` in a class scope (Ali Hamdan, PR [17038](https://github.com/python/mypy/pull/17038)) +- Fix emulating hash method logic in `attrs` classes (Hashem, PR [17016](https://github.com/python/mypy/pull/17016)) +- Add reverted typeshed commit that uses `ParamSpec` for `functools.wraps` (Tamir Duberstein, PR [16942](https://github.com/python/mypy/pull/16942)) +- Fix type narrowing for `types.EllipsisType` (Shantanu, PR [17003](https://github.com/python/mypy/pull/17003)) +- Fix single item enum match type exhaustion (Oskari Lehto, PR [16966](https://github.com/python/mypy/pull/16966)) +- Improve type inference with empty collections (Marc Mueller, PR [16994](https://github.com/python/mypy/pull/16994)) +- Fix override checking for decorated property (Shantanu, PR [16856](https://github.com/python/mypy/pull/16856)) +- Fix narrowing on match with function subject (Edward Paget, PR [16503](https://github.com/python/mypy/pull/16503)) +- Allow `+N` within `Literal[...]` (Spencer Brown, PR [16910](https://github.com/python/mypy/pull/16910)) +- Experimental: Support TypedDict within `type[...]` (Marc Mueller, PR [16963](https://github.com/python/mypy/pull/16963)) +- Experimtental: Fix issue with TypedDict with optional keys in `type[...]` (Marc Mueller, PR [17068](https://github.com/python/mypy/pull/17068)) #### Acknowledgements Thanks to all mypy contributors who contributed to this release: