More types

This section introduces a few additional kinds of types, including NoReturn,NewType, TypedDict, and types for async code. It also discusseshow to give functions more precise types using overloads. All of these are onlysituationally useful, so feel free to skip this section and come back when youhave a need for some of them.

Here’s a quick summary of what’s covered here:

• NoReturn lets you tell mypy that a function never returns normally.
• NewType lets you define a variant of a type that is treated as aseparate type by mypy but is identical to the original type at runtime.For example, you can have UserId as a variant of int that isjust an int at runtime.
• @overload lets you define a function that can accept multiple distinctsignatures. This is useful if you need to encode a relationship between thearguments and the return type that would be difficult to express normally.
• TypedDict lets you give precise types for dictionaries that representobjects with a fixed schema, such as {'id': 1, 'items': ['x']}.
• Async types let you type check programs using async and await.