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 with 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://marketplace.visualstudio.com/items?itemName=ms-pyright.pyright) that implements the [Language Server Protocol](https://microsoft.github.io/language-server-protocol/).
For rich Python editing and debugging capabilities 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.
For most VS Code users, we recommend using the Pylance extension rather than Pyright. Pylance incorporates the Pyright type checker but features additional capabilities such as IntelliCode and semantic token highlighting. You can install the latest-published version of the Pylance VS Code extension directly from VS Code. Simply open the extensions panel and search for “Pylance”.
Alternatively, [ALE](https://github.com/dense-analysis/ale) will automatically check your code with Pyright, without requiring any additional configuration.
Sublime text users can install the [LSP-pyright](https://github.com/sublimelsp/LSP-pyright) plugin from [package control](https://packagecontrol.io/packages/LSP-pyright).
A [community-maintained](https://github.com/RobertCraigie/pyright-python) Python package by the name of “pyright” is available on pypi and conda-forge. This package will automatically install node (which Pyright requires) and keep Pyright up to date.
`pip install pyright`
or
`conda install pyright`
Once installed, you can run the tool from the command line as follows:
`pyright <options>`
Alternatively, you can install the command-line version of Pyright directly from npm, which is part of node. If you don't have a recent version of node on your system, install that first from [nodejs.org](https://nodejs.org).
For additional information about Python static typing, refer to this community-maintained [Python Type School](https://github.com/python/typing/discussions).
Do you have questions about Pyright or Python type annotations in general? Post your questions in [the discussion section](https://github.com/microsoft/pyright/discussions).
If you would like to report a bug or request an enhancement, file a new issue in either the [pyright](https://github.com/microsoft/pyright/issues) or [pylance-release](https://github.com/microsoft/pylance-release/issues) issue tracker. In general, core type checking functionality is associated with Pyright while language service functionality is associated with Pylance, but the same contributors monitor both repos. For best results, provide the information requested in the issue template.
**A:** Pyright is an open-source Python type checker and language server. Pylance leverages Pyright’s functionality with additional features, some of which are not open-sourced.
**A:** Pyright is an officially-supported Microsoft type checker for Python. It will continue to be developed and maintained as an open-source project under its original MIT license terms. The Pyright extension for VS Code is a reference implementation and is not guaranteed to be fully functional or maintained long-term.
This project welcomes contributions and suggestions. For feature and complex bug fix contributions, it is recommended that you first discuss the proposed change with Pyright’s maintainers before submitting the pull request. 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.
