While duck typing is certainly seen as a feature by many Python programmers, sometimes — especially for larger codebases — type checking can be useful, too. For that reason a number of type annotations are proposed as Python Enhancement Proposals (PEPs), and Pyright is a type checker that works with these annotations. In addition, it provides some type inference and guards that understand conditional code flow constructs. Designed with large codebases in mind, Pyright is fast, and its watch mode checks happen incrementally as files are changed to further shorten the feedback cycle. Pyright can be used directly on the command line, but integrations for VS Code, Emacs, vim, Sublime, and possibly other editors are available, too. In our experience, Pyright is preferable to alternatives like mypy.
