Skip to content
This repository has been archived by the owner on Oct 31, 2023. It is now read-only.

Update mypy to 1.6.1 #228

Open
wants to merge 1 commit into
base: master
Choose a base branch
from
Open

Update mypy to 1.6.1 #228

wants to merge 1 commit into from

Conversation

pyup-bot
Copy link
Collaborator

This PR updates mypy from 1.2.0 to 1.6.1.

Changelog

1.6

[Tuesday, 10 October 2023](https://mypy-lang.blogspot.com/2023/10/mypy-16-released.html)

We’ve just uploaded mypy 1.6 to the Python Package Index ([PyPI](https://pypi.org/project/mypy/)). Mypy is a static type checker for Python. This release includes new features, performance improvements 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](http://mypy.readthedocs.io).

Introduce Error Subcodes for Import Errors

Mypy now uses the error code import-untyped if an import targets an installed library that doesn’t support static type checking, and no stub files are available. Other invalid imports produce the import-not-found error code. They both are subcodes of the import error code, which was previously used for both kinds of import-related errors.

Use \--disable-error-code=import-untyped to only ignore import errors about installed libraries without stubs. This way mypy will still report errors about typos in import statements, for example.

If you use \--warn-unused-ignore or \--strict, mypy will complain if you use \ type: ignore\[import\] to ignore an import error. You are expected to use one of the more specific error codes instead. Otherwise, ignoring the import error code continues to silence both errors.

This feature was contributed by Shantanu (PR [15840](https://github.com/python/mypy/pull/15840), PR [14740](https://github.com/python/mypy/pull/14740)).

Remove Support for Targeting Python 3.6 and Earlier

Running mypy with \--python-version 3.6, for example, is no longer supported. Python 3.6 hasn’t been properly supported by mypy for some time now, and this makes it explicit. This was contributed by Nikita Sobolev (PR [15668](https://github.com/python/mypy/pull/15668)).

Selective Filtering of \--disallow-untyped-calls Targets

Using \--disallow-untyped-calls could be annoying when using libraries with missing type information, as mypy would generate many errors about code that uses the library. Now you can use \--untyped-calls-exclude=acme, for example, to disable these errors about calls targeting functions defined in the acme package. Refer to the [documentation](https://mypy.readthedocs.io/en/latest/command_line.html#cmdoption-mypy-untyped-calls-exclude) for more information.

This feature was contributed by Ivan Levkivskyi (PR [15845](https://github.com/python/mypy/pull/15845)).

Improved Type Inference between Callable Types

Mypy now does a better job inferring type variables inside arguments of callable types. For example, this code fragment now type checks correctly:

python
def f(c: Callable[[T, S], None]) -> Callable[[str, T, S], None]: ...
def g(*x: int) -> None: ...

reveal_type(f(g))   Callable[[str, int, int], None]


This was contributed by Ivan Levkivskyi (PR [15910](https://github.com/python/mypy/pull/15910)).

Don’t Consider None and TypeVar to Overlap in Overloads

Mypy now doesn’t consider an overload item with an argument type None to overlap with a type variable:

python
overload
def f(x: None) -> None: ..
overload
def f(x: T) -> Foo[T]: ...
...


Previously mypy would generate an error about the definition of f above. This is slightly unsafe if the upper bound of T is object, since the value of the type variable could be None. We relaxed the rules a little, since this solves a common issue.

This feature was contributed by Ivan Levkivskyi (PR [15846](https://github.com/python/mypy/pull/15846)).

Improvements to \--new-type-inference

The experimental new type inference algorithm (polymorphic inference) introduced as an opt-in feature in mypy 1.5 has several improvements:

*   Improve transitive closure computation during constraint solving (Ivan Levkivskyi, PR [15754](https://github.com/python/mypy/pull/15754))
*   Add support for upper bounds and values with \--new-type-inference (Ivan Levkivskyi, PR [15813](https://github.com/python/mypy/pull/15813))
*   Basic support for variadic types with \--new-type-inference (Ivan Levkivskyi, PR [15879](https://github.com/python/mypy/pull/15879))
*   Polymorphic inference: support for parameter specifications and lambdas (Ivan Levkivskyi, PR [15837](https://github.com/python/mypy/pull/15837))
*   Invalidate cache when adding \--new-type-inference (Marc Mueller, PR [16059](https://github.com/python/mypy/pull/16059))

**Note:** We are planning to enable \--new-type-inference by default in mypy 1.7. Please try this out and let us know if you encounter any issues.

ParamSpec Improvements

*   Support self-types containing ParamSpec (Ivan Levkivskyi, PR [15903](https://github.com/python/mypy/pull/15903))
*   Allow “…” in Concatenate, and clean up ParamSpec literals (Ivan Levkivskyi, PR [15905](https://github.com/python/mypy/pull/15905))
*   Fix ParamSpec inference for callback protocols (Ivan Levkivskyi, PR [15986](https://github.com/python/mypy/pull/15986))
*   Infer ParamSpec constraint from arguments (Ivan Levkivskyi, PR [15896](https://github.com/python/mypy/pull/15896))
*   Fix crash on invalid type variable with ParamSpec (Ivan Levkivskyi, PR [15953](https://github.com/python/mypy/pull/15953))
*   Fix subtyping between ParamSpecs (Ivan Levkivskyi, PR [15892](https://github.com/python/mypy/pull/15892))

Stubgen Improvements

*   Add option to include docstrings with stubgen (chylek, PR [13284](https://github.com/python/mypy/pull/13284))
*   Add required ... initializer to NamedTuple fields with default values (Nikita Sobolev, PR [15680](https://github.com/python/mypy/pull/15680))

Stubtest Improvements

*   Fix \_\_mypy-replace false positives (Alex Waygood, PR [15689](https://github.com/python/mypy/pull/15689))
*   Fix edge case for bytes enum subclasses (Alex Waygood, PR [15943](https://github.com/python/mypy/pull/15943))
*   Generate error if typeshed is missing modules from the stdlib (Alex Waygood, PR [15729](https://github.com/python/mypy/pull/15729))
*   Fixes to new check for missing stdlib modules (Alex Waygood, PR [15960](https://github.com/python/mypy/pull/15960))
*   Fix stubtest enum.Flag edge case (Alex Waygood, PR [15933](https://github.com/python/mypy/pull/15933))

Documentation Improvements

*   Do not advertise to create your own assert\_never helper (Nikita Sobolev, PR [15947](https://github.com/python/mypy/pull/15947))
*   Fix all the missing references found within the docs (Albert Tugushev, PR [15875](https://github.com/python/mypy/pull/15875))
*   Document await-not-async error code (Shantanu, PR [15858](https://github.com/python/mypy/pull/15858))
*   Improve documentation of disabling error codes (Shantanu, PR [15841](https://github.com/python/mypy/pull/15841))

Other Notable Changes and Fixes

*   Make unsupported PEP 695 features (introduced in Python 3.12) give a reasonable error message (Shantanu, PR [16013](https://github.com/python/mypy/pull/16013))
*   Remove the \--py2 command-line argument (Marc Mueller, PR [15670](https://github.com/python/mypy/pull/15670))
*   Change empty tuple from tuple\[\] to tuple\[()\] in error messages (Nikita Sobolev, PR [15783](https://github.com/python/mypy/pull/15783))
*   Fix assert\_type failures when some nodes are deferred (Nikita Sobolev, PR [15920](https://github.com/python/mypy/pull/15920))
*   Generate error on unbound TypeVar with values (Nikita Sobolev, PR [15732](https://github.com/python/mypy/pull/15732))
*   Fix over-eager types-google-cloud-ndb suggestion (Shantanu, PR [15347](https://github.com/python/mypy/pull/15347))
*   Fix type narrowing of \== None and in (None,) conditions (Marti Raudsepp, PR [15760](https://github.com/python/mypy/pull/15760))
*   Fix inference for attrs.fields (Shantanu, PR [15688](https://github.com/python/mypy/pull/15688))
*   Make “await in non-async function” a non-blocking error and give it an error code (Gregory Santosa, PR [15384](https://github.com/python/mypy/pull/15384))
*   Add basic support for decorated overloads (Ivan Levkivskyi, PR [15898](https://github.com/python/mypy/pull/15898))
*   Fix TypeVar regression with self types (Ivan Levkivskyi, PR [15945](https://github.com/python/mypy/pull/15945))
*   Add \_\_match\_args\_\_ to dataclasses with no fields (Ali Hamdan, PR [15749](https://github.com/python/mypy/pull/15749))
*   Include stdout and stderr in dmypy verbose output (Valentin Stanciu, PR [15881](https://github.com/python/mypy/pull/15881))
*   Improve match narrowing and reachability analysis (Shantanu, PR [15882](https://github.com/python/mypy/pull/15882))
*   Support \_\_bool\_\_ with Literal in \--warn-unreachable (Jannic Warken, PR [15645](https://github.com/python/mypy/pull/15645))
*   Fix inheriting from generic frozen attrs class (Ilya Priven, PR [15700](https://github.com/python/mypy/pull/15700))
*   Correctly narrow types for tuple\[type\[X\], ...\] (Nikita Sobolev, PR [15691](https://github.com/python/mypy/pull/15691))
*   Don't flag intentionally empty generators unreachable (Ilya Priven, PR [15722](https://github.com/python/mypy/pull/15722))
*   Add tox.ini to mypy sdist (Marcel Telka, PR [15853](https://github.com/python/mypy/pull/15853))
*   Fix mypyc regression with pretty (Shantanu, PR [16124](https://github.com/python/mypy/pull/16124))

Typeshed Updates

Typeshed is now modular and distributed as separate PyPI packages for everything except the standard library stubs. Please see [git log](https://github.com/python/typeshed/commits/main?after=6a8d653a671925b0a3af61729ff8cf3f90c9c662+0&branch=main&path=stdlib) for full list of typeshed changes.

Acknowledgements

Thanks to Max Murin, who did most of the release manager work for this release (I just did the final steps).

Thanks to all mypy contributors who contributed to this release:

*   Albert Tugushev
*   Alex Waygood
*   Ali Hamdan
*   chylek
*   EXPLOSION
*   Gregory Santosa
*   Ilya Priven
*   Ivan Levkivskyi
*   Jannic Warken
*   KotlinIsland
*   Marc Mueller
*   Marcel Johannesmann
*   Marcel Telka
*   Mark Byrne
*   Marti Raudsepp
*   Max Murin
*   Nikita Sobolev
*   Shantanu
*   Valentin Stanciu

Posted by Jukka Lehtosalo

1.5

[Thursday, 10 August 2023](https://mypy-lang.blogspot.com/2023/08/mypy-15-released.html)

We’ve just uploaded mypy 1.5 to the Python Package Index ([PyPI](https://pypi.org/project/mypy/)). Mypy is a static type checker for Python. This release includes new features, deprecations 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](http://mypy.readthedocs.io).

Drop Support for Python 3.7

Mypy no longer supports running with Python 3.7, which has reached end-of-life. This was contributed by Shantanu (PR [15566](https://github.com/python/mypy/pull/15566)).

Optional Check to Require Explicit override

If you enable the explicit-override error code, mypy will generate an error if a method override doesn’t use the typing.override decorator (as discussed in [PEP 698](https://peps.python.org/pep-0698/#strict-enforcement-per-project)). This way mypy will detect accidentally introduced overrides. Example:

python
mypy: enable-error-code="explicit-override"

from typing_extensions import override

class C:
 def foo(self) -> None: pass
 def bar(self) -> None: pass

class D(C):
  Error: Method "foo" is not using override but is
  overriding a method
 def foo(self) -> None:
     ...

 override
 def bar(self) -> None:   OK
     ...


You can enable the error code via \--enable-error-code=explicit-override on the mypy command line or enable\_error\_code = explicit-override in the mypy config file.

The override decorator will be available in typing in Python 3.12, but you can also use the backport from a recent version of `typing_extensions` on all supported Python versions.

This feature was contributed by Marc Mueller(PR [15512](https://github.com/python/mypy/pull/15512)).

More Flexible TypedDict Creation and Update

Mypy was previously overly strict when type checking TypedDict creation and update operations. Though these checks were often technically correct, they sometimes triggered for apparently valid code. These checks have now been relaxed by default. You can enable stricter checking by using the new \--extra-checks flag.

Construction using the `**` syntax is now more flexible:

python
from typing import TypedDict

class A(TypedDict):
 foo: int
 bar: int

class B(TypedDict):
 foo: int

a: A = {"foo": 1, "bar": 2}
b: B = {"foo": 3}
a2: A = { **a, **b}   OK (previously an error)


You can also call update() with a TypedDict argument that contains a subset of the keys in the updated TypedDict:
python
a.update(b)   OK (previously an error)


This feature was contributed by Ivan Levkivskyi (PR [15425](https://github.com/python/mypy/pull/15425)).

Deprecated Flag: \--strict-concatenate

The behavior of \--strict-concatenate is now included in the new \--extra-checks flag, and the old flag is deprecated.

Optionally Show Links to Error Code Documentation

If you use \--show-error-code-links, mypy will add documentation links to (many) reported errors. The links are not shown for error messages that are sufficiently obvious, and they are shown once per error code only.

Example output:

a.py:1: error: Need type annotation for "foo" (hint: "x: List[<type>] = ...")  [var-annotated]
a.py:1: note: See https://mypy.rtfd.io/en/stable/_refs.html#code-var-annotated for more info

This was contributed by Ivan Levkivskyi (PR [15449](https://github.com/python/mypy/pull/15449)).

Consistently Avoid Type Checking Unreachable Code

If a module top level has unreachable code, mypy won’t type check the unreachable statements. This is consistent with how functions behave. The behavior of \--warn-unreachable is also more consistent now.

This was contributed by Ilya Priven (PR [15386](https://github.com/python/mypy/pull/15386)).

Experimental Improved Type Inference for Generic Functions

You can use \--new-type-inference to opt into an experimental new type inference algorithm. It fixes issues when calling a generic functions with an argument that is also a generic function, in particular. This current implementation is still incomplete, but we encourage trying it out and reporting bugs if you encounter regressions. We are planning to enable the new algorithm by default in a future mypy release.

This feature was contributed by Ivan Levkivskyi (PR [15287](https://github.com/python/mypy/pull/15287)).

Partial Support for Python 3.12

Mypy and mypyc now support running on recent Python 3.12 development versions. Not all new Python 3.12 features are supported, and we don’t ship compiled wheels for Python 3.12 yet.

*   Fix ast warnings for Python 3.12 (Nikita Sobolev, PR [15558](https://github.com/python/mypy/pull/15558))
*   mypyc: Fix multiple inheritance with a protocol on Python 3.12 (Jukka Lehtosalo, PR [15572](https://github.com/python/mypy/pull/15572))
*   mypyc: Fix self-compilation on Python 3.12 (Jukka Lehtosalo, PR [15582](https://github.com/python/mypy/pull/15582))
*   mypyc: Fix 3.12 issue with pickling of instances with \_\_dict\_\_ (Jukka Lehtosalo, PR [15574](https://github.com/python/mypy/pull/15574))
*   mypyc: Fix i16 on Python 3.12 (Jukka Lehtosalo, PR [15510](https://github.com/python/mypy/pull/15510))
*   mypyc: Fix int operations on Python 3.12 (Jukka Lehtosalo, PR [15470](https://github.com/python/mypy/pull/15470))
*   mypyc: Fix generators on Python 3.12 (Jukka Lehtosalo, PR [15472](https://github.com/python/mypy/pull/15472))
*   mypyc: Fix classes with \_\_dict\_\_ on 3.12 (Jukka Lehtosalo, PR [15471](https://github.com/python/mypy/pull/15471))
*   mypyc: Fix coroutines on Python 3.12 (Jukka Lehtosalo, PR [15469](https://github.com/python/mypy/pull/15469))
*   mypyc: Don't use \_PyErr\_ChainExceptions on 3.12, since it's deprecated (Jukka Lehtosalo, PR [15468](https://github.com/python/mypy/pull/15468))
*   mypyc: Add Python 3.12 feature macro (Jukka Lehtosalo, PR [15465](https://github.com/python/mypy/pull/15465))

Improvements to Dataclasses

*   Improve signature of dataclasses.replace (Ilya Priven, PR [14849](https://github.com/python/mypy/pull/14849))
*   Fix dataclass/protocol crash on joining types (Ilya Priven, PR [15629](https://github.com/python/mypy/pull/15629))
*   Fix strict optional handling in dataclasses (Ivan Levkivskyi, PR [15571](https://github.com/python/mypy/pull/15571))
*   Support optional types for custom dataclass descriptors (Marc Mueller, PR [15628](https://github.com/python/mypy/pull/15628))
*   Add `__slots__` attribute to dataclasses (Nikita Sobolev, PR [15649](https://github.com/python/mypy/pull/15649))
*   Support better \_\_post\_init\_\_ method signature for dataclasses (Nikita Sobolev, PR [15503](https://github.com/python/mypy/pull/15503))

Mypyc Improvements

*   Support unsigned 8-bit native integer type: mypy\_extensions.u8 (Jukka Lehtosalo, PR [15564](https://github.com/python/mypy/pull/15564))
*   Support signed 16-bit native integer type: mypy\_extensions.i16 (Jukka Lehtosalo, PR [15464](https://github.com/python/mypy/pull/15464))
*   Define mypy\_extensions.i16 in stubs (Jukka Lehtosalo, PR [15562](https://github.com/python/mypy/pull/15562))
*   Document more unsupported features and update supported features (Richard Si, PR [15524](https://github.com/python/mypy/pull/15524))
*   Fix final NamedTuple classes (Richard Si, PR [15513](https://github.com/python/mypy/pull/15513))
*   Use C99 compound literals for undefined tuple values (Jukka Lehtosalo, PR [15453](https://github.com/python/mypy/pull/15453))
*   Don't explicitly assign NULL values in setup functions (Logan Hunt, PR [15379](https://github.com/python/mypy/pull/15379))

Stubgen Improvements

*   Teach stubgen to work with complex and unary expressions (Nikita Sobolev, PR [15661](https://github.com/python/mypy/pull/15661))
*   Support ParamSpec and TypeVarTuple (Ali Hamdan, PR [15626](https://github.com/python/mypy/pull/15626))
*   Fix crash on non-str docstring (Ali Hamdan, PR [15623](https://github.com/python/mypy/pull/15623))

Documentation Updates

*   Add documentation for additional error codes (Ivan Levkivskyi, PR [15539](https://github.com/python/mypy/pull/15539))
*   Improve documentation of type narrowing (Ilya Priven, PR [15652](https://github.com/python/mypy/pull/15652))
*   Small improvements to protocol documentation (Shantanu, PR [15460](https://github.com/python/mypy/pull/15460))
*   Remove confusing instance variable example in cheat sheet (Adel Atallah, PR [15441](https://github.com/python/mypy/pull/15441))

Other Notable Fixes and Improvements

*   Constant fold additional unary and binary expressions (Richard Si, PR [15202](https://github.com/python/mypy/pull/15202))
*   Exclude the same special attributes from Protocol as CPython (Kyle Benesch, PR [15490](https://github.com/python/mypy/pull/15490))
*   Change the default value of the slots argument of attrs.define to True, to match runtime behavior (Ilya Priven, PR [15642](https://github.com/python/mypy/pull/15642))
*   Fix type of class attribute if attribute is defined in both class and metaclass (Alex Waygood, PR [14988](https://github.com/python/mypy/pull/14988))
*   Handle type the same as typing.Type in the first argument of classmethods (Erik Kemperman, PR [15297](https://github.com/python/mypy/pull/15297))
*   Fix \--find-occurrences flag (Shantanu, PR [15528](https://github.com/python/mypy/pull/15528))
*   Fix error location for class patterns (Nikita Sobolev, PR [15506](https://github.com/python/mypy/pull/15506))
*   Fix re-added file with errors in mypy daemon (Ivan Levkivskyi, PR [15440](https://github.com/python/mypy/pull/15440))
*   Fix dmypy run on Windows (Ivan Levkivskyi, PR [15429](https://github.com/python/mypy/pull/15429))
*   Fix abstract and non-abstract variant error for property deleter (Shantanu, PR [15395](https://github.com/python/mypy/pull/15395))
*   Remove special casing for "cannot" in error messages (Ilya Priven, PR [15428](https://github.com/python/mypy/pull/15428))
*   Add runtime `__slots__` attribute to attrs classes (Nikita Sobolev, PR [15651](https://github.com/python/mypy/pull/15651))
*   Add get\_expression\_type to CheckerPluginInterface (Ilya Priven, PR [15369](https://github.com/python/mypy/pull/15369))
*   Remove parameters that no longer exist from NamedTuple.\_make() (Alex Waygood, PR [15578](https://github.com/python/mypy/pull/15578))
*   Allow using typing.Self in `__all__` with an explicit staticmethod decorator (Erik Kemperman, PR [15353](https://github.com/python/mypy/pull/15353))
*   Fix self types in subclass methods without Self annotation (Ivan Levkivskyi, PR [15541](https://github.com/python/mypy/pull/15541))
*   Check for abstract class objects in tuples (Nikita Sobolev, PR [15366](https://github.com/python/mypy/pull/15366))

Typeshed Updates

Typeshed is now modular and distributed as separate PyPI packages for everything except the standard library stubs. Please see [git log](https://github.com/python/typeshed/commits/main?after=fc7d4722eaa54803926cee5730e1f784979c0531+0&branch=main&path=stdlib) for full list of typeshed changes.

Acknowledgements

Thanks to all mypy contributors who contributed to this release:

*   Adel Atallah
*   Alex Waygood
*   Ali Hamdan
*   Erik Kemperman
*   Federico Padua
*   Ilya Priven
*   Ivan Levkivskyi
*   Jelle Zijlstra
*   Jared Hance
*   Jukka Lehtosalo
*   Kyle Benesch
*   Logan Hunt
*   Marc Mueller
*   Nikita Sobolev
*   Richard Si
*   Shantanu
*   Stavros Ntentos
*   Valentin Stanciu

Posted by Valentin Stanciu

1.4

[Tuesday, 20 June 2023](https://mypy-lang.blogspot.com/2023/06/mypy-140-released.html)

We’ve just uploaded mypy 1.4 to the Python Package Index ([PyPI](https://pypi.org/project/mypy/)). Mypy is a static type checker for Python. This release includes new features, performance improvements 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](http://mypy.readthedocs.io).

The Override Decorator

Mypy can now ensure that when renaming a method, overrides are also renamed. You can explicitly mark a method as overriding a base class method by using the typing.override decorator ([PEP 698](https://peps.python.org/pep-0698/)). If the method is then renamed in the base class while the method override is not, mypy will generate an error. The decorator will be available in typing in Python 3.12, but you can also use the backport from a recent version of `typing_extensions` on all supported Python versions.

This feature was contributed byThomas M Kehrenberg (PR [14609](https://github.com/python/mypy/pull/14609)).

Propagating Type Narrowing to Nested Functions

Previously, type narrowing was not propagated to nested functions because it would not be sound if the narrowed variable changed between the definition of the nested function and the call site. Mypy will now propagate the narrowed type if the variable is not assigned to after the definition of the nested function:

python
def outer(x: str | None = None) -> None:
 if x is None:
     x = calculate_default()
 reveal_type(x)   "str" (narrowed)

 def nested() -> None:
     reveal_type(x)   Now "str" (used to be "str | None")

 nested()


This may generate some new errors because asserts that were previously necessary may become tautological or no-ops.

This was contributed by Jukka Lehtosalo (PR [15133](https://github.com/python/mypy/pull/15133)).

Narrowing Enum Values Using “==”

Mypy now allows narrowing enum types using the \== operator. Previously this was only supported when using the is operator. This makes exhaustiveness checking with enum types more usable, as the requirement to use the is operator was not very intuitive. In this example mypy can detect that the developer forgot to handle the value MyEnum.C in example

python
from enum import Enum

class MyEnum(Enum):
 A = 0
 B = 1
 C = 2

def example(e: MyEnum) -> str:   Error: Missing return statement
 if e == MyEnum.A:
     return 'x'
 elif e == MyEnum.B:
     return 'y'


Adding an extra elif case resolves the error:

python
...
def example(e: MyEnum) -> str:   No error -- all values covered
 if e == MyEnum.A:
     return 'x'
 elif e == MyEnum.B:
     return 'y'
 elif e == MyEnum.C:
     return 'z'


This change can cause false positives in test cases that have assert statements like assert o.x == SomeEnum.X when using \--strict-equality. Example:

python
mypy: strict-equality

from enum import Enum

class MyEnum(Enum):
 A = 0
 B = 1

class C:
 x: MyEnum
 ...

def test_something() -> None:
 c = C(...)
 assert c.x == MyEnum.A
 c.do_something_that_changes_x()
 assert c.x == MyEnum.B   Error: Non-overlapping equality check


These errors can be ignored using \ type: ignore\[comparison-overlap\], or you can perform the assertion using a temporary variable as a workaround:

python
...
def test_something() -> None:
 ...
 x = c.x
 assert x == MyEnum.A   Does not narrow c.x
 c.do_something_that_changes_x()
 x = c.x
 assert x == MyEnum.B   OK


This feature was contributed by Shantanu (PR [11521](https://github.com/python/mypy/pull/11521)).

Performance Improvements

*   Speed up simplification of large union types and also fix a recursive tuple crash (Shantanu, PR [15128](https://github.com/python/mypy/pull/15128))
*   Speed up union subtyping (Shantanu, PR [15104](https://github.com/python/mypy/pull/15104))
*   Don't type check most function bodies when type checking third-party library code, or generally when ignoring errors (Jukka Lehtosalo, PR [14150](https://github.com/python/mypy/pull/14150))

Improvements to Plugins

*   attrs.evolve: Support generics and unions (Ilya Konstantinov, PR [15050](https://github.com/python/mypy/pull/15050))
*   Fix ctypes plugin (Alex Waygood)

Fixes to Crashes

*   Fix a crash when function-scope recursive alias appears as upper bound (Ivan Levkivskyi, PR [15159](https://github.com/python/mypy/pull/15159))
*   Fix crash on follow\_imports\_for\_stubs (Ivan Levkivskyi, PR [15407](https://github.com/python/mypy/pull/15407))
*   Fix stubtest crash in explicit init subclass (Shantanu, PR [15399](https://github.com/python/mypy/pull/15399))
*   Fix crash when indexing TypedDict with empty key (Shantanu, PR [15392](https://github.com/python/mypy/pull/15392))
*   Fix crash on NamedTuple as attribute (Ivan Levkivskyi, PR [15404](https://github.com/python/mypy/pull/15404))
*   Correctly track loop depth for nested functions/classes (Ivan Levkivskyi, PR [15403](https://github.com/python/mypy/pull/15403))
*   Fix crash on joins with recursive tuples (Ivan Levkivskyi, PR [15402](https://github.com/python/mypy/pull/15402))
*   Fix crash with custom ErrorCode subclasses (Marc Mueller, PR [15327](https://github.com/python/mypy/pull/15327))
*   Fix crash in dataclass protocol with self attribute assignment (Ivan Levkivskyi, PR [15157](https://github.com/python/mypy/pull/15157))
*   Fix crash on lambda in generic context with generic method in body (Ivan Levkivskyi, PR [15155](https://github.com/python/mypy/pull/15155))
*   Fix recursive type alias crash in make\_simplified\_union (Ivan Levkivskyi, PR [15216](https://github.com/python/mypy/pull/15216))

Improvements to Error Messages

*   Use lower-case built-in collection types such as list\[…\] instead of List\[…\] in errors when targeting Python 3.9+ (Max Murin, PR [15070](https://github.com/python/mypy/pull/15070))
*   Use X | Y union syntax in error messages when targeting Python 3.10+ (Omar Silva, PR [15102](https://github.com/python/mypy/pull/15102))
*   Use type instead of Type in errors when targeting Python 3.9+ (Rohit Sanjay, PR [15139](https://github.com/python/mypy/pull/15139))
*   Do not show unused-ignore errors in unreachable code, and make it a real error code (Ivan Levkivskyi, PR [15164](https://github.com/python/mypy/pull/15164))
*   Don’t limit the number of errors shown by default (Rohit Sanjay, PR [15138](https://github.com/python/mypy/pull/15138))
*   Improver message for truthy functions (madt2709, PR [15193](https://github.com/python/mypy/pull/15193))
*   Output distinct types when type names are ambiguous (teresa0605, PR [15184](https://github.com/python/mypy/pull/15184))
*   Update message about invalid exception type in try (AJ Rasmussen, PR [15131](https://github.com/python/mypy/pull/15131))
*   Add explanation if argument type is incompatible because of an unsupported numbers type (Jukka Lehtosalo, PR [15137](https://github.com/python/mypy/pull/15137))
*   Add more detail to 'signature incompatible with supertype' messages for non-callables (Ilya Priven, PR [15263](https://github.com/python/mypy/pull/15263))

Documentation Updates

*   Add \--local-partial-types note to dmypy docs (Alan Du, PR [15259](https://github.com/python/mypy/pull/15259))
*   Update getting started docs for mypyc for Windows (Valentin Stanciu, PR [15233](https://github.com/python/mypy/pull/15233))
*   Clarify usage of callables regarding type object in docs (Viicos, PR [15079](https://github.com/python/mypy/pull/15079))
*   Clarify difference between disallow\_untyped\_defs and disallow\_incomplete\_defs (Ilya Priven, PR [15247](https://github.com/python/mypy/pull/15247))
*   Use attrs and attrs.define in documentation and tests (Ilya Priven, PR [15152](https://github.com/python/mypy/pull/15152))

Mypyc Improvements

*   Fix unexpected TypeError for certain variables with an inferred optional type (Richard Si, PR [15206](https://github.com/python/mypy/pull/15206))
*   Inline math literals (Logan Hunt, PR [15324](https://github.com/python/mypy/pull/15324))
*   Support unpacking mappings in dict display (Richard Si, PR [15203](https://github.com/python/mypy/pull/15203))

Changes to Stubgen

*   Do not remove Generic from base classes (Ali Hamdan, PR [15316](https://github.com/python/mypy/pull/15316))
*   Support yield from statements (Ali Hamdan, PR [15271](https://github.com/python/mypy/pull/15271))
*   Fix missing total from TypedDict class (Ali Hamdan, PR [15208](https://github.com/python/mypy/pull/15208))
*   Fix call-based namedtuple omitted from class bases (Ali Hamdan, PR [14680](https://github.com/python/mypy/pull/14680))
*   Support TypedDict alternative syntax (Ali Hamdan, PR [14682](https://github.com/python/mypy/pull/14682))
*   Make stubgen respect MYPY\_CACHE\_DIR (Henrik Bäärnhielm, PR [14722](https://github.com/python/mypy/pull/14722))
*   Fixes and simplifications (Ali Hamdan, PR [15232](https://github.com/python/mypy/pull/15232))

Other Notable Fixes and Improvements

*   Fix nested async functions when using TypeVar value restriction (Jukka Lehtosalo, PR [14705](https://github.com/python/mypy/pull/14705))
*   Always allow returning Any from lambda (Ivan Levkivskyi, PR [15413](https://github.com/python/mypy/pull/15413))
*   Add foundation for TypeVar defaults (PEP 696) (Marc Mueller, PR [14872](https://github.com/python/mypy/pull/14872))
*   Update semantic analyzer for TypeVar defaults (PEP 696) (Marc Mueller, PR [14873](https://github.com/python/mypy/pull/14873))
*   Make dict expression inference more consistent (Ivan Levkivskyi, PR [15174](https://github.com/python/mypy/pull/15174))
*   Do not block on duplicate base classes (Nikita Sobolev, PR [15367](https://github.com/python/mypy/pull/15367))
*   Generate an error when both staticmethod and classmethod decorators are used (Juhi Chandalia, PR [15118](https://github.com/python/mypy/pull/15118))
*   Fix assert\_type behaviour with literals (Carl Karsten, PR [15123](https://github.com/python/mypy/pull/15123))
*   Fix match subject ignoring redefinitions (Vincent Vanlaer, PR [15306](https://github.com/python/mypy/pull/15306))
*   Support `__all__`.remove (Shantanu, PR [15279](https://github.com/python/mypy/pull/15279))

Typeshed Updates

Typeshed is now modular and distributed as separate PyPI packages for everything except the standard library stubs. Please see [git log](https://github.com/python/typeshed/commits/main?after=877e06ad1cfd9fd9967c0b0340a86d0c23ea89ce+0&branch=main&path=stdlib) for full list of typeshed changes.

Acknowledgements

Thanks to all mypy contributors who contributed to this release:

*   Adrian Garcia Badaracco
*   AJ Rasmussen
*   Alan Du
*   Alex Waygood
*   Ali Hamdan
*   Carl Karsten
*   dosisod
*   Ethan Smith
*   Gregory Santosa
*   Heather White
*   Henrik Bäärnhielm
*   Ilya Konstantinov
*   Ilya Priven
*   Ivan Levkivskyi
*   Juhi Chandalia
*   Jukka Lehtosalo
*   Logan Hunt
*   madt2709
*   Marc Mueller
*   Max Murin
*   Nikita Sobolev
*   Omar Silva
*   Özgür
*   Richard Si
*   Rohit Sanjay
*   Shantanu
*   teresa0605
*   Thomas M Kehrenberg
*   Tin Tvrtković
*   Tushar Sadhwani
*   Valentin Stanciu
*   Viicos
*   Vincent Vanlaer
*   Wesley Collin Wright
*   William Santosa
*   yaegassy

I’d also like to thank my employer, Dropbox, for supporting mypy development.

Posted by Jared Hance

1.3

[Wednesday, 10 May 2023](https://mypy-lang.blogspot.com/2023/05/mypy-13-released.html)

We’ve just uploaded mypy 1.3 to the Python Package Index ([PyPI](https://pypi.org/project/mypy/)). Mypy is a static type checker for Python. This release includes new features, performance improvements 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](http://mypy.readthedocs.io).

Performance Improvements

*   Improve performance of union subtyping (Shantanu, PR [15104](https://github.com/python/mypy/pull/15104))
*   Add negative subtype caches (Ivan Levkivskyi, PR [14884](https://github.com/python/mypy/pull/14884))

Stub Tooling Improvements

*   Stubtest: Check that the stub is abstract if the runtime is, even when the stub is an overloaded method (Alex Waygood, PR [14955](https://github.com/python/mypy/pull/14955))
*   Stubtest: Verify stub methods or properties are decorated with final if they are decorated with final at runtime (Alex Waygood, PR [14951](https://github.com/python/mypy/pull/14951))
*   Stubtest: Fix stubtest false positives with TypedDicts at runtime (Alex Waygood, PR [14984](https://github.com/python/mypy/pull/14984))
*   Stubgen: Support functools.cached\_property (Nikita Sobolev, PR [14981](https://github.com/python/mypy/pull/14981))
*   Improvements to stubgenc (Chad Dombrova, PR [14564](https://github.com/python/mypy/pull/14564))

Improvements to attrs

*   Add support for converters with TypeVars on generic attrs classes (Chad Dombrova, PR [14908](https://github.com/python/mypy/pull/14908))
*   Fix attrs.evolve on bound TypeVar (Ilya Konstantinov, PR [15022](https://github.com/python/mypy/pull/15022))

Documentation Updates

*   Improve async documentation (Shantanu, PR [14973](https://github.com/python/mypy/pull/14973))
*   Improvements to cheat sheet (Shantanu, PR [14972](https://github.com/python/mypy/pull/14972))
*   Add documentation for bytes formatting error code (Shantanu, PR [14971](https://github.com/python/mypy/pull/14971))
*   Convert insecure links to use HTTPS (Marti Raudsepp, PR [14974](https://github.com/python/mypy/pull/14974))
*   Also mention overloads in async iterator documentation (Shantanu, PR [14998](https://github.com/python/mypy/pull/14998))
*   stubtest: Improve allowlist documentation (Shantanu, PR [15008](https://github.com/python/mypy/pull/15008))
*   Clarify "Using types... but not at runtime" (Jon Shea, PR [15029](https://github.com/python/mypy/pull/15029))
*   Fix alignment of cheat sheet example (Ondřej Cvacho, PR [15039](https://github.com/python/mypy/pull/15039))
*   Fix error for callback protocol matching against callable type object (Shantanu, PR [15042](https://github.com/python/mypy/pull/15042))

Error Reporting Improvements

*   Improve bytes formatting error (Shantanu, PR [14959](https://github.com/python/mypy/pull/14959))

Mypyc Improvements

*   Fix unions of bools and ints (Tomer Chachamu, PR [15066](https://github.com/python/mypy/pull/15066))

Other Fixes and Improvements

*   Fix narrowing union types that include Self with isinstance (Christoph Tyralla, PR [14923](https://github.com/python/mypy/pull/14923))
*   Allow objects matching SupportsKeysAndGetItem to be unpacked (Bryan Forbes, PR [14990](https://github.com/python/mypy/pull/14990))
*   Check type guard validity for staticmethods (EXPLOSION, PR [14953](https://github.com/python/mypy/pull/14953))
*   Fix sys.platform when cross-compiling with emscripten (Ethan Smith, PR [14888](https://github.com/python/mypy/pull/14888))

Typeshed Updates

Typeshed is now modular and distributed as separate PyPI packages for everything except the standard library stubs. Please see [git log](https://github.com/python/typeshed/commits/main?after=b0ed50e9392a23e52445b630a808153e0e256976+0&branch=main&path=stdlib) for full list of typeshed changes.

Acknowledgements

Thanks to all mypy contributors who contributed to this release:

*   Alex Waygood
*   Amin Alaee
*   Bryan Forbes
*   Chad Dombrova
*   Charlie Denton
*   Christoph Tyralla
*   dosisod
*   Ethan Smith
*   EXPLOSION
*   Ilya Konstantinov
*   Ivan Levkivskyi
*   Jon Shea
*   Jukka Lehtosalo
*   KotlinIsland
*   Marti Raudsepp
*   Nikita Sobolev
*   Ondřej Cvacho
*   Shantanu
*   sobolevn
*   Tomer Chachamu
*   Yaroslav Halchenko

Posted by Wesley Collin Wright.
Links

@pyup-bot pyup-bot mentioned this pull request Oct 18, 2023
Closed
Sign up for free to subscribe to this conversation on GitHub. Already have an account? Sign in.
Reviewers
No reviews
Assignees
No one assigned
Labels
None yet
Projects
None yet
Milestone
No milestone
Development

Successfully merging this pull request may close these issues.

None yet
1 participant
@pyup-bot