For the actual type annotations themselves, the official docs are great: https://docs.python.org/3/library/typing.html https://docs.python.org/3/library/typing.

For the actual type annotations themselves, the official docs are great: https://docs.python.org/3/library/typing.html https://docs.python.org/3/library/typing.html Know that the signatures vary with version, so select the correct one. To check these annotations, you'll need a third-party type checker somewhere in your build process. I use pylance with VS Code, as it can detect errors as I type: https://marketplace.visualstudio.com/items?itemName=ms-python.vscode-pylance https://marketplace.visualstudio.com/items?itemName=ms-pytho...