Is there a particular reason why the prefect codebase uses the type pattern

value: NonNullableType = None

? I understand the motivation behind it but in the end, the type is wrong and mypy will complain. Is there a setting for mypy I am missing?

Hi @José Duarte — that syntax is currently valid for mypy, it infers that the

NonNullableType

is actually

Optional[NonNullableType]

. Perhaps you are running mypy with the

--no-implicit-optional

flag, which disables this type of inference? (docs). Interestingly, mypy is currently evaluating a two-year-old proposal to make

-noo-implicit-optional

the default, but it has not been done yet AFAIK