pytype

New features and updates:

• Completely remove the --attribute-variable-annotations flag. This was a no-op as of version 2021.10.11.
• Enable --preserve-union-macros by default and make the flag a no-op. It will be removed in the next release.

Bug fixes:

• Enum overlay: fix crash due to loading __new__ from a PyTDClass.
• Enum overlay: use ClassVar to differentiate enum class attributes.
• Fix a parser bug involving nested class name conflicts.
• Fix a crash when lazily loading a missing submodule.
• Change PrintVisitor to group explicit imports with the ones collected from type annotations.

New features and updates:

• Update pytype and typing annotation stubs for features added in attrs 21.1.0.
• Enable --attribute-variable-annotations by default and make the flag a no-op. It will be removed in the next release.
• The --use-enum-overlay flag is ready for general use. Enable this flag for precise typing of the stdlib enum library.

Bug fixes:

• Support quoted types as annotations in pyi files.
• Add precise overloads for the map function.
• Support Ellipsis annotations in pyi files.
• Preserve None in unions containing Any.
• Fix a pyi import printing bug.
• Improve ignored-abstractmethod error message.
• Teach convert._load_late_type to handle nested classes.

Bug fixes:

• Call init_class instead of instantiate when adding assertIsInstance bindings.
• Use the namedtuple 'defaults' argument when generating new signature.
• Do not raise a parser error for unrecognised decorators.
• Merge BaseValue.cls and BaseValue.get_class().
• Check Instance.maybe_missing_members earlier during attribute access.
• Fix a bug in matching callables with TypeVar parameters.

New features and updates:

• Drop target Python 3.5 support.
• Remove the no-op --enforce-noniterable-strings flag.
• Support arbitrary python values for typing.Annotated in pyi files.
• Add more extensive type support for attr converters.

Bug fixes:

• Preserve named args in a function call when we have **kwargs in the arglist.
• Allow assertIsInstance to take a tuple of classes.
• Fix a bug in matching a Union against a TypeVar.
• Attach a line number to function call errors caused by annotating self.
• Add some missing namedtuple args.

New features and updates:

• Enable --enforce-noniterable-strings by default and make the flag a no-op. It will be removed in the next release.
• Narrow the types of local variables based on test assertions.
• For bad return type annotations on generators, change invalid-type-annotation to bad-yield-annotation error.
• Slightly improve pytype's performance on a trivial file.

Bug fixes:

• Fix our type definition for BaseException.with_traceback().
• Add some missing 3.8 methods to typing stubs.
• Add breakpoint to the supported builtin methods.
• Fix a bug in pytype's handling of late annotations.
• Typeshed: fix version parsing regex.

New features and updates:

• Update typeshed pin to commit 8da23e0 from July 30.
• Remove all Python 2 compatibility code.
• Print method signatures in the error message for a protocol type mismatch.
• Raise an error when comparing incompatible primitive types.

Bug fixes:

• Fix bugs in constant folding of f-strings.
• Fix a bug where typing_extensions.Protocol was treated as Any.
• Emit a pyi-error for an invalid annotation in a pyi file instead of crashing.
• Add an extra check to forbid matching Mapping too broadly.

New features and updates:

• Stop supporting target Python 2.
• Enable constant folding, a performance optimization that significantly speeds up analysis of large data structure literals.

Bug fixes:

• Replace ParamSpec.{args,kwargs} with Any.

New features and updates:

• This is the last release of pytype that supports analyzing code in Python 2.7. From the next release onward, pytype will only support Python 3.5+.
• Add a typing FAQ.
• Add a pytype_extensions.Dataclass protocol for matching any dataclass.

Bug fixes:

• Use [invalid-annotation] rather than [not-supported-yet] to report stray TypeVars in variable annotations.
• Fix bugs in attribute matching for Protocol.
• Fix a bug in pytype's import resolution for relative imports.

New features and updates:

• Add more detailed [name-error] messages for UnboundLocalError and the like.
• Remove --check-parameter-types. Its behavior has been the default since version 2021.07.19.
• Support generic namedtuples.
• Fix bugs and add features for --use-enum-overlay.
• Add a flag, --enforce-noniterable-strings, that forbids implicit iteration over strings.
• Add support for attr converters.

Bug fixes:

• Get rid of a spurious 'appear only once in signature' TypeVar error.
• Fix a few protocol matching bugs.
• Fix exception handling bugs by tracking the frame state within try/except/finally blocks.

New features and updates:

• Add a flag, --use-enum-overlay, for greatly improved support for the stdlib enum library. The behavior of this flag will be enabled by default once it is stable.
• Default --check-parameter-types to True.
• Take advantage of submodule version information in typeshed/stdlib/VERSIONS.
• typing.Protocol: support non-method attributes and modules, make error messages more detailed, and fix several bugs.
• Remove --create-pyi-dataclasses and make its behavior the default.
• Do not try doing dead block elimination within try/except blocks.

Bug fixes:

• Handle unions correctly when dealing with exception types.
• Support adding typing.Mapping as a chex.dataclass base class.
• Get rid of some incorrect 'appears only once in signature' TypeVar errors.
• Fix a pyi error caused by _PropertyToConstant not recognizing imported TypeVars.
• Allow more cases of valid typevars in variable annotations, typing.cast, and attr.ib's 'type' argument.
• Allow bound class methods to match object.
• Allow bytearray.contains to accept bytes.

New features and updates:

• Open source pytype_extensions, a library of type system extensions for use with pytype.
• Add an assert_type statement to assert pytype's view of an expression type.
• Remove the [key-error] error class: it found few real type errors and produced many false positives.

Bug fixes:

• Fix a bug that caused 'self' to be typed as 'Any' in @property bodies (temporarily requires --bind-properties flag).
• Add support for multiple and chained assignments in pyi files.
• Support the 'Protocol[T, ...]' shorthand for generic protocols.
• Typeshed: support py2-only third-party packages with no top-level stubs.

New features and updates:

• Add support for referencing class-scoped TypeVars in variable annotations.
• Add support for generic dataclasses and attrs.

Bug fixes:

• Fix a performance regression in pytype/pytd/typeshed.py.
• Generate mutations from init parameter annotations in stubs.
• Use the typeshed stub for the array module instead of a custom one.

New features and updates:

• Add support for PEP 604 (Union |) in stub files.

Bug fixes:

• Get rid of special_builtins.Filter.
• Fix circular import issues in the pytd loader.

New features and updates:

• Allow TypeGuard to be used in type stubs by rewriting TypeGuard[X] to bool.

Bug fixes:

• Fix the order of inherited attributes for dataclasses.
• Change the type of path from Iterable to List.
• Add a replace() method to flax dataclasses.

Bug fixes:

• Report [not-supported-yet] instead of [import-error] for importing TypedDict.
• Fix a bug in attribute lookup from parent classes.
• Fix a Python 3.7 failure in typeshed/tests/pytype_test.py.
• pytd: populated mutated_type from annotated self parameters.
• Preserve kw_only attribute when inheriting attrs from a different module.
• Add a vm state to allow recursive construction of pytd values.

New features and updates:

• Update typeshed pin to commit 2c8cb60 from Apr 27.

Bug fixes:

• Add typing._Alias.
• Pin attrs to 20.3.0.

New features and updates:

• Remove --check-attribute-types, --check-container-types, and --check-variable-types flags. Their behaviors are now enabled by default.
• Add a temporary --preserve-union-macros flag that preserves Union generic type aliases in type stubs. This behavior will ultimately be enabled by default and the flag removed.
• Support max versions in typeshed VERSIONS file.

Bug fixes:

• Add typing.GenericMeta stub.
• Fix handling of typeshed/stdlib/@python2.

New features and updates:

• Enable --check-attribute-types, --check-container-types, and --check-variable-types by default. These flags will soon be removed.
• Add a fix suggestion for [annotation-type-mismatch] with a None value.
• Add a temporary --attribute-variable-annotations flag that applies PEP 526-style annotations on attribute assignments. This behavior will ultimately be enabled by default and the flag removed.
• Add a temporary --create-pyi-dataclasses flag that creates dataclasses from @dataclass-annotated classes in type stubs. This behavior will ultimately be enabled by default and the flag removed.

Bug fixes:

• Don't lose track of attributes when @typing.final is used.
• Fix generation of type information for nested typing.NamedTuple classes.
• Fix some bugs in handling of generic type aliases.
• Fix a pytype crash on a generic protocol.
• For method aliasing in pyi files, consider base classes when doing lookup.

New features and updates:

• Update typeshed pin to commit ce24720 from Jan 27, and drop support for the old typeshed directory structure.
• Delete the --check-nonnull-parameter-types flag.

Bug fixes:

• Add "from typing import overload" statement when using @overload.
• Add object.delattr to our builtins stubs.
• Add some more support for generic type aliases.

New features and updates:

• Enable --check-parameter-types by default for non-None default values.
• Add some minimal support for PEP 612 in type stubs.
• Add support for typing.Annotated in pyi files.

Bug fixes:

• Fix a crash when analysed code accessed an undefined closure cell.
• Fix a minor bug in pytype's expansion of Protocol[T].
• Check starargs and starstarargs when gathering TypeVars in function sigs.
• Fix some bugs in pytype's handling of the new typeshed directory structure.
• Make sure collections.defaultdict.__init__ always accepts kwargs.
• Filter out properties from class attributes when constructing dataclasses.
• Add gi_* fields to Generators.

New features and updates:

• Add basic Python 3.9 support.

Bug fixes:

• Fully support method aliasing in stub files.
• Improve pytype's handling of sets.

New features and updates:

• Support inheritance from dataclasses defined in pyi files.

Bug fixes:

• Don't check attribute values against types from pyi files.
• Add a missing array.array.frombytes method.
• Fix the pyi type of attributes annotated with class type parameters.
• Allow annotation-type-mismatch directives to be put on more sensible lines.
• Pass ninja relative paths instead of absolute ones.

New features and updates:

• Basic support for defining dataclasses in pyi files.
• Enable more of --check-attribute-types by default.
• Get rid of the legacy pyi parser.

Bug fixes:

• Fix a circular import error (#760).
• Make NotImplementedType inherit from bool.
• Fix a caching bug that caused incorrect function parameter defaults.

New features and updates:

• Enable part of --check-attribute-types by default.

Bug fixes:

• Allow callable constants to match protocol methods.
• Allow builtins.tuple to be used for a heterogeneous tuple annotation.
• Don't report [not-instantiable] when instantiating an abstract annotation.
• Take a TypeVar's bound into account when instantiating it in attribute.py.
• Use typeshed stubs in preference to empty stubs.
• Fix a bug where multiple definitions of a TypeVar could end up in a stub.
• Fix a caching bug in check_container_types.
• Fix initialization of Union types in forward references.

New features and updates:

• Support running pytype under Python 3.9. (Does not yet support analyzing 3.9 code; see details in https://github.com/google/pytype/pull/840.)
• Update typeshed pin to commit 869238e from Jan 26.

Bug fixes:

• Do stricter filtering of container_type_mismatch errors.
• Preserve the concrete value of TYPE_CHECKING in method bodies.
• Support using collections.abc.Callable in type stubs.

Bug fixes:

• Fix 'nothing' parameter inference for self in custom generic classes.
• Fix several cases of class type parameters being instantiated incorrectly.
• Fix an if-splitting bug by (mostly) ignoring cycles in the CFG.
• Use match_var_against_type, not match_from_mro, for check_container_types.

New features and updates:

• Replace namedtuples with attrs in our PyTD representation.

Bug fixes:

• Improve error messaging for typing.AnyStr.
• Fully qualify std::size_t to avoid platform incompatibilities.
• Add isascii attribute to str, bytes, and bytearray.
• Support isinstance() checks on tuples of typing containers.
• Improve *args and **kwargs forwarding for attrs and dataclasses.
• Don't propagate attribute errors for deleted names.

New features:

• Update typeshed pin to commit 8c20938 from Nov 13.
• Implement basic support for PEP 593.
• Support typeshed's new directory structure.

Bug fixes:

• Support aliases attr.attrs for attr.s, and attr.attrib for attr.ib.
• --check-container-types: fix a crash and improve the error message.

• Switch to a typed_ast-based stub parser.
• Fix matching of NamedType against LiteralType in --protocols mode.
• Fix: super() in a list comprehension needs to look at the enclosing frame.

• Fix some corner cases with unpacking and function args.
• Add ImportError attributes name, path for Python 3.3+.
• Unbreak annotate-ast by adding an empty pytype/ast/init.py file.