ty 0.0.21

on Python PyPI

Release Notes

Released on 2026-03-05.

Bug fixes

• Avoid stack overflow with recursive typevar (#23652)
• Fix panic on incomplete except handlers (#23708)
• Allow unions of different-length iterables in *args unpacking into optional positional parameters (#23124)
• Don't replace Any attributes with object after isinstance narrowing (#23725)

LSP server

• Exclude decorators from class/def code folding (#23543)
• Fix handling of non-Python text documents (#23704)

Configuration

• Add all selector to ty.json schema (#23721)
• Fix precedence of all selector in TOML configurations (#23723)
• Make all selector case-sensitive (#23713)

Type checking

• Add invalid-enum-member-annotation lint rule (#23648)
• Add a diagnostic for an unused awaitable (#23650)
• Add a diagnostic if a TypeVar is used to specialize a ParamSpec, or vice versa (#23738)
• Add more type-variable default validation (#23639)
• Add unbound type variable detection in annotations (#23641)
• Apply narrowing to walrus values (#23687)
• Do not union Unknown into unannotated container types (#23718)
• Avoid inferring generics with negative intersections (#23750)
• More precise types for name and value of an enum (#23683)
• Better preserve user-provided union order in inferred specializations (#23715)
• Support narrowing in ternary expressions (#23726)
• Validate bare ParamSpec usage in type annotations, and support stringified ParamSpecs as the first argument to Callable (#23625)

Contributors

• @charliermarsh
• @zsol
• @Gankra
• @MichaReiser
• @AlexWaygood
• @rizzip
• @iksuddle
• @dcreager
• @BurntSushi
• @carljm
• @oconnor663

Install ty 0.0.21

Install prebuilt binaries via shell script

curl --proto '=https' --tlsv1.2 -LsSf https://github.com/astral-sh/ty/releases/download/0.0.21/ty-installer.sh | sh

Install prebuilt binaries via powershell script

powershell -ExecutionPolicy Bypass -c "irm https://github.com/astral-sh/ty/releases/download/0.0.21/ty-installer.ps1 | iex"

Download ty 0.0.21