Typeerror: Object of Type Is Not Json Serializable
I'm Wrote Rest on the Flask Using Flask-Marshmallow Models. Py Class Application(Db. Model): __Tablename__ = 'Applications' Id = Db. Column(Db. String()...
I'm wrote rest on the Flask using flask-marshmallow
models.py
class Application(db.Model):
__tablename__ = 'applications'
id = db.Column(db.String(), primary_key=True)
name = db.Column(db.String())
versions = db.relationship('Version', backref='application', lazy=True)
def __repr__(self):
return '<application {}>'.format(self.name)
class Version(db.Model):
__tablename__ = 'versions'
id = db.Column(db.String(), primary_key=True)
file = db.Column(db.String(80), nullable=True)
application_id = db.Column(db.Integer, db.ForeignKey('applications.id'))
shemas.py
class ApplicationDetailSchema(ma.Schema):
class Meta:
fields = ('id', 'name', 'versions')
routes.py
@bp.route("/<id>")
def application_detail(id):
application = Application.query.get(id)
result = application_detail_schema.dump(application)
return jsonify(result)
TypeError: Object of type 'Version' is not JSON serializable
4 Answers
You probably want to use ModelSchema instead of Schema.
class ApplicationDetailSchema(ma.ModelSchema):
class Meta:
model = Application
fields = ('id', 'name', 'versions')
ModelSchema dumps the related foreign key objects as a list of id(s) by default which is JSON serializable.
In order to use jsonify() you have to make serializable the class you need to jsonify. Add to that class a function similar to the following:
class Version(db.Model):
__tablename__ = 'versions'
id = db.Column(db.String(), primary_key=True)
file = db.Column(db.String(80), nullable=True)
application_id = db.Column(db.Integer, db.ForeignKey('applications.id'))
def serialize(self):
return {"id": self.id,
"file": self.file,
"application_id": self.application_id}
And then jsonify de serializaed version of the object, and not the objetc itself:
jsonify(result.serialize())
This method work for me
class User(db.Model, Timestamp):
id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String(20), nullable= False)
email = db.Column(db.String(40), unique = True, nullable= False)
def toDict(self):
return dict(id=self.id, name=self.id email=self.email)
and
return jsonify([s.toDict() for s in admins])
Try with json.dumps() and json.loads()
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