pyre-check VS pyright

Did you come across pyre in your search? MIT license and pretty fast.

https://github.com/facebook/pyre-check

Pyre is a performant type-checker developed by Facebook. Pyre can analyse codebases with millions of lines of code incrementally – providing instantaneous feedback to developers as they write code.

Pyre from Meta, pyright from Microsoft and PyType from Google provide additional assistance. They can 'infer' types based on code flow and existing types within the code.

Have you seen Pyre[0]? Not Rust, OCaml, and pretty fast. Made by a team at Meta and open sourced on GitHub. If you use python-lsp, I wrote an extension[1] to enable integration (though I haven't tested it recently, been programming in rust; it is mostly a "for me" extension).

0: https://pyre-check.org/

1: https://github.com/cricalix/python-lsp-pyre

Internally we use Pyre for Python type checking: https://github.com/facebook/pyre-check

Before type hinting, work had intense rules and linters enforcing docstrings with types. Now, type hints and automatic pyre runs take care of all the heavy lifting.

Python now has an optional type system and if you add one of them such as mypy or pyre to your CI process and you can configure GitHub to refuse the pull request until types are added you can make it somewhat strongly typed.

If you have a preexisting codebase I believe the way you can convert it is to add the types that you know on commits and eventually you will have enough types that adding the missing ones should be easy. For the missing ones Any is a good choice.

https://pyre-check.org and https://github.com/python/mypy are popular.

mypy (and pyright occasionally) as a type checker,

They identified this as a bug and fixed it, then changed course and decided to reinstate the behaviour. So if you want to write idiomatic Python, you need to disable typechecking TypedDicts.

— https://github.com/microsoft/pyright/issues/1739

Now if this were a linter then I would understand. But a type checker should not be opinionated to the point of pushing people not to use idiomatic Python.

Pyright:

This is a good summary: https://github.com/microsoft/pyright/blob/main/docs/mypy-com...

But without that, I always felt like I was actively fighting mypy. It seemed like it was written for a totally different language than Python.

Compared to another more modern type system like TypeScript, sometimes you don't explicitly type something and yet TypeScript usually does exactly what you expect.

We have it already: https://github.com/microsoft/pyright

Python (pyright)

Pyright is billed as a "static type checker" but its a full-blown language server (which pylance is built on). I've used both pylance and pyright and frankly I haven't seen any benefit going up to pylance. Pyright is under the MIT license so it can be used for anything: https://github.com/microsoft/pyright/blob/main/LICENSE.txt

disclaimer: I don't work on big codebases.

Pylance with pyright[0] while developing (with strict mode) and mypy[1] with pre-commit and CI.

Previously, I had to rely on pyright in pre-commit and CI for a while because mypy didn’t support PEP 695 until its 1.11 release in July.

[0] -- https://github.com/microsoft/pyright

[1] -- https://github.com/python/mypy

Static Type Checking with PyRight: Improve code quality and reduce bugs with PyRight, a static type checking feature not available in R. This proactive error detection ensures your applications are reliable, before you even start them.