Re: [PULL 3/5] qemu-iotests: 300: Add test case for modifying persistence of bitmap

[John Snow <jsnow@redhat.com>]

On 2/15/21 1:25 PM, Eric Blake wrote:
> -BlockBitmapMapping = List[Dict[str, Union[str, List[Dict[str, str]]]]]
> +BlockBitmapMapping = List[Dict[str,
> +                               Union[str,
> +                                     List[Dict[str,
> +                                               Union[str, Dict[str,
> bool]]]]]]]

That looks *very* beefy.

Is the Union because that union is valid for every key, or because every 
key has a potentially different value that is specific to that key?

if it's the latter, I'd ditch the Union and just go with:

Dict[str, object], or
Dict[str, Any]

object: will allow any type, but keeps strict checking enabled. If you 
try to use that value later on without a cast, mypy will warn you if you 
are using it in a manner not guaranteed by the "object" type. Can be 
useful if you are passing values to a function that already does RTTI to 
determine behavior.

Any: Also allows any type, but enables gradual typing. If you later 
"assume" the type of this value, mypy will say nothing. Can be useful 
when you've just got a job to do and the right tool would have been a 
recursive type or a TypedDict (unavailable in Python 3.6.)

--js