ListAttribute of NumberAttributes not recognized as float by mypy

[jkirsch-patreon]

When a MapAttribute is defined with an attribute of ListAttribute(of=NumberAttribute), mypy does not recognize the individual elements of the ListAttribute as float. This is not an issue with MapAttributes defined with NumberAttributes.

Example

class ExampleAttribute(MapAttribute):
    ids = ListAttribute(null=False, of=NumberAttribute)


# mypy complains
# No overload variant of "int" matches argument type "NumberAttribute"mypycall-overload
example = ExampleAttribute()
result = [int(x) for x in example.ids]

# reveal_type(x) : NumberAttribute

class MapWithNumber(MapAttribute):
    x = NumberAttribute()


# no issues
m = MapWithNumber()
int(m.x)

pynamodb version: pynamodb==5.5.0
mypy version: 1.8.0
python: 3.9.16