Pytype

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.