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pythonmarshmallow

Validating optional field in marshmallow

I have a field in my model which is required in the resource body while creating the resource (POST) and is not passed in the request body(will be passed along with URL) while updating the resource (PUT).

I have created my marshmallow model:

class DummySchema():
   field_1 = fields.Str(required=True)
   field_2 = fields.Id()

If I leave field_1 to required=True, I get the following error on PUT :

{
    "message": {
        "field_1": [
            "Missing data for required field."
        ]
    }
}

I could leave it required in the model, but that would mean it would cause a problem in POST request.

Is there a way I could set the field as optional, but set it required for my POST request so that I can perform my validation?

Solution

  • I think I should've read the documentation thoroughly before :(

    I could set a field as partial, so when it'll do validation marshmallow would skip the field

    data, errors = DummySchema().load({'field_2': 42}, partial=('field_1',))

    REF: https://marshmallow.readthedocs.io/en/2.x-line/quickstart.html#validation