ty 0.0.15

on Python PyPI

Release Notes

Released on 2026-02-04.

Bug fixes

• Add support for resolving imports of packages installed into Debian/Ubuntu dist-packages directories (#22466)
• Avoid not-iterable false positives when iterating over an instance of an intersection type with only negated elements (#22089)
• Fix support for stringized annotations in very large files (#22913)
• Don't emit Liskov diagnostics for methods with mangled names (#23062)
• Enforce that a Final symbol cannot be reassigned even after a conditional binding (#22986)
• Fix TypedDict construction from existing TypedDict values (#22904)
• Fix Self resolution for classes nested within methods (#22964)
• Fix bidirectional inference with PEP 695 union type aliases (#22988)
• Fix edge-case bugs when narrowing tagged unions in match statements (#22870)
• Fix false-positive diagnostics when iterating over an instance of an intersection that includes a TypeVar of which the upper bound is a union where the union includes a non-iterable type (#22117)
• Fix lookup of __contains__ to respect descriptors (#23056)
• Fix narrowing of nonlocal variables with conditional assignments (#22966)
• Fix several bugs that could affect NewTypes of NewTypes of float (#22997)
• Fix several type narrowing bugs involving PEP-695 type aliases (#22894)
• Fix spurious query cycles in decorated functions with parameter defaults, for improved performance and improved determinism (#23014)
• Fix unary and comparison operators for TypeVars with union bounds (#22925)
• Understand functions as method descriptors even if they are decorated with a decorator annotated as returning a PEP-695 alias to a Callable type (#22902)
• dataclass_transform: Fix visibility of field specifiers when models are nested inside methods (#23069)

LSP server

• Fix hover showing Unknown for bare Final instance attributes (#23003)
• Improve support for goto-type, goto-declaration, hover, and highlighting of string annotations (#22878)
• Include setters and deleters when renaming properties (#22999)
• Show type qualifiers like Final in on-hover hints (#23005)

Configuration

• Add new unused-type-ignore-comment rule (#22790)
• Add a mechanism to ignore/warn/select all rules (#22832)
• Support multiple workspace folders in a single ty LSP server instance (#22953)
• Only add ./src as a search path if ./src/__init__.py(i) does not exist (#22851)

Type checking

• Add a diagnostic detecting if a variable is declared as Final but never has any bindings (#23001)
• Add a diagnostic detecting overridden comparison dunder methods on order=True dataclasses (#22689)
• Add a hint to invalid-argument-type and invalid-assignment diagnostics if a variable is annotated with a type from the numbers module (#22931, #22938)
• Add diagnostic hint on unresolved-reference to suggest using "list" instead of "List" (#22827)
• Add new diagnostic for invalid dataclass field orders (#19825)
• Allow a subclass method with a positional-only parameter to override a superclass method without that parameter if the parameter in the subclass method has a default value (#23037)
• Allow self-referential imports outside the global scope (#22963)
• Ban ... in odd places inside tuple specializations (#22889)
• Ban Required, NotRequired and ReadOnly in parameter annotations (#22888)
• Ban legacy TypeVar bounds or constraints from containing type variables (#22949)
• Ban multiple unpacked variadic tuples in a tuple specialization (#22884)
• Detect generic Callables in the return type of function signatures (#22954)
• Detect invalid isinstance() and issubclass() calls against TypedDict classes (#22887)
• Detect invalid issubclass() calls against Protocol classes with non-method members (#22896)
• Detect invalid attempts to subclass Protocol[] and Generic[] simultaneously (#22948)
• Emit a diagnostic on incorrect applications of the legacy convention for specifying positional-only parameters (#22943)
• Emit an error if a TypeVarTuple is used to subscript Generic or Protocol without being unpacked (#22952)
• Fallback to metaclass __getattr__ or __getattribute__ when looking up attributes on class objects (#22985)
• Fix a bug where an overridden type in a dataclass subclass would not be respected if the dataclass subclass field had a default value but the superclass field did not (#22965)
• Improve bidirectional type inference involving PEP-695 type aliases (#22989)
• Improve detection of invalid NewTypes with generic bases (#22961)
• Improve reachability analysis when evaluating the truthiness of expressions that involve variables that may not be bound in all code paths (#22971)
• Improve the error message if ** is used with a non-mapping in the context of a call to an overloaded function (#22921)
• Infer ParamSpec from class constructors for callable protocols (#22853)
• Move the location of some invalid-overload diagnostics (#22933)
• Point to an overload with an invalid @final decorator when emitting invalid-overload errors for invalid @final decorators (#22893)
• Avoid false positives when iterating over an instance of an intersection with only negated elements by preserving "pure negation" types in descriptor lookups (#22907)
• Promote Literal types when inferring elements for very large unannotated tuples, for improved performance (#22841)
• Recognize functions with stub bodies in Protocol classes as implicitly abstract (#22838)
• Reduce false positives involving heterogeneous dicts by tracking dictionary literal keys as individual places (#22882)
• Reduce false positives when subscripting classes generic over TypeVarTuples (#22950)
• Remove special handling for Any() in match class patterns (#23011)
• Support type[None] in type expressions (#22892)
• Support legacy namespace packages declared using pkg_resources.declare_namespace (#22987)
• Sync vendored typeshed stubs (#23006), Typeshed diff
• Validate signatures of dataclass __post_init__ methods (#22730)

Contributors

• @charliermarsh
• @stefanvanburen
• @ibraheemdev
• @abhijeetbodas2001
• @MichaReiser
• @dcreager
• @PrettyWood
• @sharkdp
• @oconnor663
• @Feiyang472
• @denyszhak
• @mtshiba
• @AlexWaygood
• @11happy
• @BurntSushi
• @carljm
• @Gankra
• @MentalMegalodon
• @thejchap

Install ty 0.0.15

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curl --proto '=https' --tlsv1.2 -LsSf https://github.com/astral-sh/ty/releases/download/0.0.15/ty-installer.sh | sh

Install prebuilt binaries via powershell script

powershell -ExecutionPolicy Bypass -c "irm https://github.com/astral-sh/ty/releases/download/0.0.15/ty-installer.ps1 | iex"

Download ty 0.0.15