PEP-593 added typing.Annotated as a way of adding context-specific
metadata to existing types, and specifies that Annotated[T, x] should
be treated as T by any tool or library without special logic for x.

This package provides metadata objects which can be used to represent
common constraints such as upper and lower bounds on scalar values and
collection sizes, a Predicate marker for runtime checks, and
descriptions of how we intend these metadata to be interpreted. In some
cases, we also note alternative representations which do not require
this package.

• Alexandr Shashkin

• python3-module-annotated-types