code-blockwise configuration settings

Feature

In mypy, we can do something like # type: ignore [error-code]

For some developer tools, we can use some blockwise settings, ex:

# fmt: off
blabla
# fmt: on

Momentarily configuring some mypy settings in a similar fashion would be useful

Pitch

A specific reason why I'd like to see this is that I have a codebase where allow-redefinition is False (and this is good). But I have a small region where I have a lot of type narrowing to do and in this case allowing a block of redefinitions is far more convenient. Plus, the control comments would signal to the reader that this is happening.

El issue no menciona archivos, pruebas ni puntos de entrada. Empieza revisando cómo mypy gestiona los comentarios de control en línea y configuraciones como allow-redefinition; para darlo por terminado, se requiere una sintaxis y un comportamiento acordados para la configuración con ámbito de bloque, incluido cómo se aplica la configuración dentro y fuera del bloque.