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wrong inference of function literals off subclass-of types

callables

Status: Open.

Bug

#2428 In astral-sh/ty;

· carljm opened on Jan 9, 2026

Result of max with key=len is always Sized

genericsBugs or features relating to ty's generics implementationBugs or features relating to ty's generics implementation

Status: Open.

#2572 In astral-sh/ty;

· druzsan opened on Jan 20, 2026

Properly recognize async generator functions

asyncIssues related to checking code using async/awaitIssues related to checking code using async/await

diagnosticsRelated to reporting of diagnostics.Related to reporting of diagnostics.

documentationImprovements or additions to documentationImprovements or additions to documentation

Status: Open.

#2875 In astral-sh/ty;

· niksabaldun opened on Feb 21, 2026

Default parameter values should be expressions, not types

bugSomething isn't workingSomething isn't working

Status: Open.

Bug

#1882 In astral-sh/ty;

· hamdanal opened on Dec 14, 2025

don't discard "unused" typevars from generic context of simplified generic type alias

genericsBugs or features relating to ty's generics implementationBugs or features relating to ty's generics implementation

type aliases

Status: Open.

#1846 In astral-sh/ty;

· cmp0xff opened on Dec 10, 2025

typevar solver can't solve a generic union

genericsBugs or features relating to ty's generics implementationBugs or features relating to ty's generics implementation

Status: Open.

#1703 In astral-sh/ty;

· suleymanozkeskin opened on Dec 1, 2025

pair of mutually recursive generic Protocol definitions

Protocols

Status: Open.

#1587 In astral-sh/ty;

· gertvdijk opened on Nov 18, 2025

Display of overloaded definitions

diagnosticsRelated to reporting of diagnostics.Related to reporting of diagnostics.

needs-designNeeds further design before implementationNeeds further design before implementation

overloads

Status: Open.

#102 In astral-sh/ty;

· dhruvmanila opened on May 1, 2025

Improve [unresolved-attribute] diagnostic for the case of an invalid __getattr__ method

attribute accessInstance attributes, class attributes, etc.Instance attributes, class attributes, etc.

diagnosticsRelated to reporting of diagnostics.Related to reporting of diagnostics.

Status: Open.

Feature

#135 In astral-sh/ty;

· AlexWaygood opened on Apr 6, 2025

Add support for properties with deleters

runtime semanticsAccurate modeling of how Python's semantics work at runtimeAccurate modeling of how Python's semantics work at runtime

Status: Open.

#142 In astral-sh/ty;

· sharkdp opened on Apr 2, 2025

Add proper support for class decorators

runtime semanticsAccurate modeling of how Python's semantics work at runtimeAccurate modeling of how Python's semantics work at runtime

Status: Open.

#143 In astral-sh/ty;

· sharkdp opened on Apr 2, 2025

Add an opt-in diagnostic warning about unsound calls to type[]

typing semanticstyping-module features, spec compliance, etctyping-module features, spec compliance, etc

Status: Open.

Feature

#145 In astral-sh/ty;

· AlexWaygood opened on Mar 31, 2025

full documentation

documentationImprovements or additions to documentationImprovements or additions to documentation

Status: Open.

#149 In astral-sh/ty;

· carljm opened on Mar 26, 2025

walrus expressions in a comprehension scope "leak" into the comprehension's enclosing scope

bugSomething isn't workingSomething isn't working

runtime semanticsAccurate modeling of how Python's semantics work at runtimeAccurate modeling of how Python's semantics work at runtime

Status: Open.

#162 In astral-sh/ty;

· AlexWaygood opened on Mar 24, 2025

Check the return type of dunder methods

runtime semanticsAccurate modeling of how Python's semantics work at runtimeAccurate modeling of how Python's semantics work at runtime

Status: Open.

#196 In astral-sh/ty;

· MichaReiser opened on Feb 19, 2025

Warn about too old python-version

configurationRelated to settings and configurationRelated to settings and configuration

Status: Open.

Feature

#201 In astral-sh/ty;

· MichaReiser opened on Feb 11, 2025

Diagnostic for conflicting declared attribute types

attribute accessInstance attributes, class attributes, etc.Instance attributes, class attributes, etc.

help wantedContributions especially welcomeContributions especially welcome

typing semanticstyping-module features, spec compliance, etctyping-module features, spec compliance, etc

Status: Open.

Feature

#206 In astral-sh/ty;

· sharkdp opened on Feb 5, 2025

tuple & AlwaysFalsy should simplify to tuple[()]

bugSomething isn't workingSomething isn't working

set-theoretic typesunions, intersections and moreunions, intersections and more

type propertiessubtyping, assignability, equivalence, and moresubtyping, assignability, equivalence, and more

Status: Open.

#215 In astral-sh/ty;

· AlexWaygood opened on Jan 16, 2025

AlwaysTruthy | bool is equivalent to AlwaysTruthy | Literal[False]

bugSomething isn't workingSomething isn't working

set-theoretic typesunions, intersections and moreunions, intersections and more

Status: Open.

#216 In astral-sh/ty;

· AlexWaygood opened on Jan 15, 2025

Check implementation consistency for an overloaded function

conformance

help wantedContributions especially welcomeContributions especially welcome

overloads

Status: Open.

Task

#109 In astral-sh/ty;

· dhruvmanila opened on Apr 30, 2025

Check for overlapping overloads

overloads

Status: Open.

Feature

#103 In astral-sh/ty;

· dhruvmanila opened on May 1, 2025

Implement @warnings.deprecated checking for @overrides

diagnosticsRelated to reporting of diagnostics.Related to reporting of diagnostics.

featureNew feature or requestNew feature or request

Status: Open.

#844 In astral-sh/ty;

· Gankra opened on Jul 17, 2025

Implement @warnings.deprecated checking for dunder methods and properties

diagnosticsRelated to reporting of diagnostics.Related to reporting of diagnostics.

featureNew feature or requestNew feature or request

Status: Open.

#843 In astral-sh/ty;

· Gankra opened on Jul 17, 2025

Assignment narrowing doesn't work with descriptor

attribute accessInstance attributes, class attributes, etc.Instance attributes, class attributes, etc.

narrowingrelated to flow-sensitive type narrowingrelated to flow-sensitive type narrowing

Status: Open.

#628 In astral-sh/ty;

· max-muoto opened on Jun 10, 2025

invalid-return-type false positive on constrained generic when narrowing for each constraint

genericsBugs or features relating to ty's generics implementationBugs or features relating to ty's generics implementation

narrowingrelated to flow-sensitive type narrowingrelated to flow-sensitive type narrowing

Status: Open.

#621 In astral-sh/ty;

· DetachHead opened on Jun 10, 2025