Pyright is a fast type checker meant for large Python source bases. It can run in a “watch” mode and performs fast incremental updates when files are modified.
Pyright supports [configuration files](/docs/configuration.md) that provide granular control over settings. Different “execution environments” can be associated subdirectories within a source base. Each environment can specify different module search paths, python language versions, and platform targets.
Pyright includes a recent copy of the stdlib type stubs from [Typeshed](https://github.com/python/typeshed). It can be configured to use another (perhaps more recent or modified) copy of the Typeshed type stubs. Of course, it also works with custom type stub files that are part of your project.
Pyright includes both a [command-line tool](/docs/command-line.md) and an [extension for Visual Studio Code](https://github.com/Microsoft/pyright) that implements the [Language Server Protocol](https://microsoft.github.io/language-server-protocol/).
For rich Python editing and debugging cabailities with Visual Studio Code, be sure to also install the official [Microsoft Python extension for Visual Studio Code](https://marketplace.visualstudio.com/itemdetails?itemName=ms-python.python) as Pyright only provides syntax and type checking.
Pyright is a work in progress. Type-checking capabilities are not fully implemented. For a list of incomplete functionality, refer to the TODO list below.
**A:** Pyright is focused on type checking. The Python VS Code plugin is Microsoft’s officially-supported extension for VS Code and provides a diverse array of features including auto-complete, debugging, linter plugins, type-checking plugins, and much more. Pyright can be used alongide the Microsoft Python extension.
**A:** The Microsoft Python Language Server is a [language server protocol (LSP)](https://microsoft.github.io/language-server-protocol/) implementation that works with the Microsoft Python VS Code plugin. It is officially supported by a team of Microsoft engineers. It focuses on providing core editing capabilities such as auto-completion, code navigation and documentation. Pyright is focused on providing fast syntax and type checking with features such as more configurabilty and command-line execution.
**A:** Pyright is a side project with no dedicated team. There is no guarantee of continued development on the project. If you find it useful, feel free to use it and contribute to the code base.
You can install the latest-published version of the Pyright VS Code extension directly from VS Code. Simply open the extensions panel and search for `pyright`.
This project welcomes contributions and suggestions. Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For details, visit https://cla.microsoft.com.
When you submit a pull request, a CLA-bot will automatically determine whether you need to provide a CLA and decorate the PR appropriately (e.g., label, comment). Simply follow the instructions provided by the bot. You will only need to do this once across all repos using our CLA.
This project has adopted the [Microsoft Open Source Code of Conduct](https://opensource.microsoft.com/codeofconduct/). For more information see the [Code of Conduct FAQ](https://opensource.microsoft.com/codeofconduct/faq/) or contact [opencode@microsoft.com](mailto:opencode@microsoft.com) with any additional questions or comments.