Pylance

Pylance is a Python language server and static type checker for Visual Studio Code, developed by Microsoft. It is built on Pyright, a fast type analyzer for Python, and is delivered as a VS Code extension that can be installed from the Marketplace.

Pylance offers fast IntelliSense, including autocomplete, parameter hints, and hover information, along with robust type checking and error reporting. It uses configurable type checking modes, such as off, basic, and strict, to balance safety and flexibility. The server also provides advanced code navigation features like go to definition, find references, and semantic token-based highlighting, as well as automatic imports.

Type information is derived from Python type hints and, when available, optional type stub files (.pyi) for third-party libraries. Pylance can infer types for code without explicit annotations and deliver precise diagnostics, enabling early detection of potential errors.

Pylance is integrated with the official Python extension for Visual Studio Code and is often presented as the default or recommended Python language server in VS Code. It replaces older Python language servers and aims to deliver a fast, scalable editor experience for Python projects.