pre_load many has issues in 3.5.0

In marshmallow 3.4.0 data is a list, which is what I expect, when using pass_many.

In marshmallow 3.5.0 data is a single object.

   @pre_load(pass_many=True)
    def reposition_tasks(self, data, **kwargs):
        position = 0
        for task in data:
            task["position"] = position
            position += 1
        return data

Do you have a suggestion, what I am doing wrong? Or is this a bug?

[michaeltoohig]

@lafrech Okay well I have to second this issue then and I just double checked my work. List(Nested(Schema)) does not work with pre_load on the child schema because it passes single objects instead of the many objects as it would before.

However, if I think about it a bit more I realize this means that I should change my do_something logic to handle each individual item instead of the whole list at once which makes more sense IMO. Before I was using the bug instead of fixing it and I see it now.

But perhaps the ‘issue’ I was facing could be a legitimate issue for another use case?

Thanks @lafrech and @sloria

[lafrech]

I think the question is answered. New behaviour is the correct one.