how to serialise a enum property in sqlalchemy using marshmallow

Question

this is my model class

class Type(enum.Enum):
    Certified = \"certified\"
    Non_Certified = \"non-certified\"


class Status(enum.Enum):
    Approved = \         


        

Answer 1

You can use Marshmallow custom method fields

from marshmallow import fields

class CourseSchema(ModelSchema):
    type = fields.Method("get_course_type")

    def get_course_type(self, obj):
        return obj.type.value

    class Meta:
        model = Course
        sqla_session = session

Answer 2

Another alternative is to override the __str__ method of your Enum. E.g.

class Type(enum.Enum):
    Certified = "certified"
    Non_Certified = "non-certified"

    def __str__(self):
        return self.value

Answer 3

For enum fields, the simplest approach is to install the package called marshmallow_enum via pip (pip install marshmallow_enum), importing it in your project and then in your marshmallow schema definitions override the SQLAlchemy fields with your custom definition:

from marshmallow_enum import EnumField
...


class CourseSchema(ModelSchema):
    type = EnumField(Type, by_value=True)

    class Meta:
        model = Course
        sqla_session = session

All fields that weren't overridden by your custom definitions will be taken from your model.

You can experiment with the by_value parameter, which enables you to either serialize names (by default) or values (by_value=True) of your enums.