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See original GitHub issue

Hey,

From the dictionary:

data = {
    'id': 1337,
    'profiles': [
        {'email': 'test@test.com'},
        {'email': 'old_email@test.com'},
    ]
}

Which schema could I write to dump the following result?

{
  "id": 1337,
  "current_email": "test@test.com"
}

Assuming the latest email in the first entry from profiles.

I imagine it should be possible with fields.Pluck, but I can’t make it work.

Thanks!

Issue Analytics

State:
Created 3 years ago
Comments:6 (3 by maintainers)

Top GitHub Comments

2reactions

brmzkwcommented, May 20, 2020

Indeed, it is also working. Full working example:

from marshmallow import decorators, fields, Schema

data = {
    'id': 1337,
    'profiles': [
        {'email': 'test@test.com'},
        {'email': 'old_email@test.com'},
    ]
}


class ProfileSchema(Schema):
    email = fields.String()


class UserSchema(Schema):
    id = fields.Int()

    @decorators.post_dump(pass_original=True)
    def add_email(self, data, original_data, many=False):
        data['email'] = original_data['profiles'][0]['email']
        return data


print (UserSchema().dump(data))

pass_original is important here. By default, original data is not given to post_dump.

Thanks!

0reactions

sloriacommented, May 19, 2020

Oh right, custom field isn’t what you want. You could use a post_dump method instead.