24.4.1

New error codes:

• Y066: When using if/else with sys.version_info, put the code for new Python versions first.

24.4.0

Bugfixes:

• Fix Y026 false positive: allow simple assignment to None in class scopes if the class is known to be an enum class.

24.3.1

New error codes:

• Y064: Use simpler syntax to define final literal types. For example, use x: Final = 42 instead of x: Final[Literal[42]]
• Y065: Don't use bare Incomplete in parameter and return annotations.

Bugfixes:

• Y090: Fix false positive for tuple[Unpack[Ts]].

24.3.0

New error codes:

• Y063: Use PEP 570 syntax to mark positional-only arguments, rather than the older Python 3.7-compatible syntax described in PEP 484.

24.1.0

New error codes:

• Y062: Disallow duplicate elements inside Literal[] slices.

Other features:

• Support flake8>=7.0.0
• Y061 is no longer emitted in situations where Y062 would also be emitted.
• Improve error message for Y060.
• Y023 now bans more imports from typing_extensions now that typeshed has dropped support for Python 3.7.

Bugfixes:

• Y016: Fix false positive if a method had positional-only parameters using PEP 570 syntax and the first positional-or-keyword parameter following the positional-only parameters used a custom TypeVar (see #455).
• Y046: Fix false negative where an unused protocol would not be detected if the protocol was generic.

23.11.0

New error codes:

• Y058: Use Iterator rather than Generator as the return value for simple __iter__ methods, and AsyncIterator rather than AsyncGenerator as the return value for simple __aiter__ methods.
• Y059: Generic[] should always be the last base class, if it is present in the bases of a class.
• Y060, which flags redundant inheritance from Generic[].
• Y061: Do not use None inside a Literal[] slice. For example, use Literal["foo"] | None instead of Literal["foo", None].

Other changes:

• The undocumented pyi.__version__ and pyi.PyiTreeChecker.version attributes has been removed. Use flake8 --version from the command line, or importlib.metadata.version("flake8_pyi") at runtime, to determine the version of flake8-pyi installed at runtime.
• Y038 now flags from typing_extensions import AbstractSet as well as from typing import AbstractSet.
• Y022 and Y037 now flag more imports from typing_extensions.
• Y034 now attempts to avoid flagging methods inside classes that inherit from builtins.type, abc.ABCMeta and/or enum.EnumMeta. Classes that have one or more of these as bases are metaclasses, and PEP 673 forbids the use of typing(_extensions).Self for metaclasses. While reliably determining whether a class is a metaclass in all cases would be impossible for flake8-pyi, the new heuristics should reduce the number of false positives from this check.
• Attempting to import typing_extensions.Text now causes Y039 to be emitted rather than Y023.
• Y053 will no longer be emitted for the argument to @typing_extensions.deprecated.

23.10.0

• Introduce Y090, which warns if you have an annotation such as tuple[int] or Tuple[int]. These mean "a tuple of length 1, in which the sole element is of type int". This is sometimes what you want, but more usually you'll want tuple[int, ...], which means "a tuple of arbitrary (possibly 0) length, in which all elements are of type int".

  This error code is disabled by default due to the risk of false-positive errors. To enable it, use the --extend-select=Y090 option.

• Y011 now ignores sentinel and _typeshed.sentinel in default values.

23.6.0

Features:

• Support Python 3.12
• Support PEP 695 syntax for declaring type aliases
• Correctly emit Y019 errors for PEP-695 methods that are generic around a TypeVar instead of returning typing_extensions.Self
• Introduce Y057: Do not use typing.ByteString or collections.abc.ByteString. These types have unclear semantics, and are deprecated; use typing_extensions.Buffer or a union such as bytes | bytearray | memoryview instead. See PEP 688 for more details.
• The way in which flake8-pyi modifies pyflakes runs has been improved:

  • When flake8-pyi is installed, pyflakes will now complain about forward references in default values for function and method parameters (the same as pyflakes does when it checks .py files). Unlike in .py files, forward references in default values are legal in stub files. However, they are never necessary, and are considered bad style. (Forward references for parameter annotations are still allowed.)

    Contributed by tomasr8.

  • When flake8-pyi is installed, pyflakes's F822 check now produces many fewer false positives when flake8 is run on .pyi files. It now understands that x: int in a stub file is sufficient for x to be considered "bound", and that "x" can therefore be included in __all__.

Bugfixes:

• Y018, Y046, Y047 and Y049 previously failed to detect unused TypeVars/ParamSpecs/TypeAliases/TypedDicts/Protocols if the object in question had multiple definitions in the same file (e.g. across two branches of an if sys.version_info >= (3, 10) check). This bug has now been fixed.
• Y020 was previously not emitted if quoted annotations were used in TypeVar constraints. This bug has now been fixed.

Other changes:

• flake8-pyi no longer supports being run on Python 3.7, which has reached its end of life.
• flake8-pyi no longer supports being run with flake8 <v6.

23.5.0

• flake8-pyi no longer supports being run with flake8 <5.0.4.

• The way in which flake8-pyi modifies pyflakes runs has been improved:

  • When flake8-pyi is installed, pyflakes now correctly recognises an annotation as
    being equivalent to a binding assignment in a stub file, reducing false
    positives from flake8's F821 error code.

  • When flake8-pyi is installed, there are now fewer pyflakes positives from class
    definitions that have forward references in the bases tuple for the purpose of
    creating recursive or circular type definitions. These are invalid in .py files,
    but are supported in stub files.

  • When flake8-pyi is installed, pyflakes will also complain about code which (in
    combination with flake8-pyi) it previously had no issue with. For example, it will
    now complain about this code:

    class Foo(Bar): ...
    class Bar: ...

    Although the above code is legal in a stub file, it is considered poor style, and
    the forward reference serves no purpose (there is no recursive or circular
    definition). As such, it is now disallowed by pyflakes when flake8-pyi is
    installed.

  Contributed by tomasr8.

• Introduce Y056: Various type checkers have different levels of support for method
  calls on __all__. Use __all__ += ["foo", "bar"] instead, as this is known to be
  supported by all major type checkers.

23.4.1

• Introduce Y055: Unions of the form type[X] | type[Y] can be simplified to type[X | Y]. Similarly, Union[type[X], type[Y]] can be simplified to type[Union[X, Y]]. Contributed by tomasr8.