AttributeError from /Lesson-3/20_JSON-Solution/

[Shehab-Muhammad]

I got this error

Traceback (most recent call last):
File "/usr/lib/python2.7/dist-packages/flask/app.py", line 1836, in call
return self.wsgi_app(environ, start_response)
File "/usr/lib/python2.7/dist-packages/flask/app.py", line 1820, in wsgi_app
response = self.make_response(self.handle_exception(e))
File "/usr/lib/python2.7/dist-packages/flask/app.py", line 1403, in handle_exception
reraise(exc_type, exc_value, tb)
File "/usr/lib/python2.7/dist-packages/flask/app.py", line 1817, in wsgi_app
response = self.full_dispatch_request()
File "/usr/lib/python2.7/dist-packages/flask/app.py", line 1477, in full_dispatch_request
rv = self.handle_user_exception(e)
File "/usr/lib/python2.7/dist-packages/flask/app.py", line 1381, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "/usr/lib/python2.7/dist-packages/flask/app.py", line 1475, in full_dispatch_request
rv = self.dispatch_request()
File "/usr/lib/python2.7/dist-packages/flask/app.py", line 1461, in dispatch_request
return self.view_functionsrule.endpoint
File "/vagrant/web_server/webbyflask.py", line 18, in restaurantMenuJSON
return item.serialize
AttributeError: 'MenuItem' object has no attribute 'serialize'

this my webbyflask.py

from flask import Flask, render_template, request, url_for, redirect, flash, jsonify
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
from database_setup import Base, Restaurant, MenuItem
from flask.templating import render_template
app = Flask(__name__)


engine = create_engine('sqlite:///restaurantmenu.db')
Base.metadata.bind = engine

DBSession = sessionmaker(bind=engine)
session = DBSession()

@app.route('/restaurants/<int:restaurant_id>/menu/<int:menu_id>/JSON')
def restaurantMenuJSON(restaurant_id, menu_id):
    item = session.query(MenuItem).filter_by(id = menu_id).one()
    return item.serialize

and this is my database_setup.py

import sys
import os
from sqlalchemy import Column, ForeignKey, Integer, String
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import relationship
from sqlalchemy import create_engine

Base = declarative_base()

class Restaurant(Base):
    __tablename__ = 'restaurant'
    name = Column(String(80), nullable = False)
    id = Column(Integer, primary_key = True)

class MenuItem(Base):
    __tablename__ = 'menu_item'

    name = Column(String(80), nullable = False)
    id = Column(Integer, primary_key = True)
    course = Column(String(250))
    description = Column(String(250))
    price = Column(String(8))
    restaurant_id = Column(Integer, ForeignKey('restaurant.id'))
    restaurant = relationship(Restaurant)

    @property
    def serialize(self):
        return {
            'name': self.name,
            'description': self.description,
            'id': self.id,
            'price': self.price,
            'course': self.course,
        }

[hpeddula]

Add the serialize method within the class declaration of the menu item class

[tomdecort]

Hi,

I get the same error after I join tables. So how do you join tables and return the result in JSON?

`class JobContexts(db.Model):
tablename = 'job_contexts'
table_args = {'schema':'config'}
job_context_id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String)
execution_order = db.Column(db.Integer)

def __init__(self, job_context_id, name, execution_order):
    self.job_context_id = job_context_id
    self.name = name
    self.execution_order = execution_order

@property
def json(self):
    return to_json(self, self.__class__)

@property
def serialize(self):
    """Return object data in easily serializable format"""
    return {
        'job_context_id'  : self.job_context_id,
        'name'            : self.name,
        'execution_order' : self.execution_order
    }

class Jobs(db.Model):
tablename = 'jobs'
table_args = {'schema':'config'}
job_id = db.Column(db.Integer, primary_key=True)
job_name = db.Column(db.String, nullable=False)
job_context_id = db.Column(db.Integer, db.ForeignKey('JobContexts.job_context_id'))
execution_order = db.Column(db.Integer)
active = db.Column(db.Boolean)
depending_of_jobs = db.Column(db.Integer)

def __init__(self, job_id, job_name, job_context_id, execution_order, active, depending_of_jobs):
    self.job_id = job_id
    self.job_name = job_name
    self.job_context_id = job_context_id
    self.execution_order = execution_order
    self.active = active
    self.depending_of_jobs = depending_of_jobs

@property
def json(self):
    return to_json(self, self.__class__)

@property
def serialize(self):
   """Return object data in easily serializable format"""
   return {
       'job_id'            : self.job_id,
       'job_name'          : self.job_name,
       'job_context_id'    : self.job_context_id,
       'execution_order'   : self.execution_order,
       'depending_of_jobs' : self.depending_of_jobs
   }`

and

def getAllJobs(): #return jsonify(json_list = [i.serialize for i in jobs.query.all()]) ##> works fine! all_jobs = Jobs.query.join(JobContexts, Jobs.job_context_id == JobContexts.job_context_id).add_columns(JobContexts.name).all() return jsonify([i.serialize for i in all_jobs])

Anyone knows about good documentation about flask_sqlalchemy providing more info on how to join tables etc.?

Cheers,
Tom

[VarunAdithya]

return jsonify(Menu_List =[i.serialize for i in Menu_Item])

[ppingpping]

I got this error

Traceback (most recent call last):
File "/usr/lib/python2.7/dist-packages/flask/app.py", line 1836, in call
return self.wsgi_app(environ, start_response)
File "/usr/lib/python2.7/dist-packages/flask/app.py", line 1820, in wsgi_app
response = self.make_response(self.handle_exception(e))
File "/usr/lib/python2.7/dist-packages/flask/app.py", line 1403, in handle_exception
reraise(exc_type, exc_value, tb)
File "/usr/lib/python2.7/dist-packages/flask/app.py", line 1817, in wsgi_app
response = self.full_dispatch_request()
File "/usr/lib/python2.7/dist-packages/flask/app.py", line 1477, in full_dispatch_request
rv = self.handle_user_exception(e)
File "/usr/lib/python2.7/dist-packages/flask/app.py", line 1381, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "/usr/lib/python2.7/dist-packages/flask/app.py", line 1475, in full_dispatch_request
rv = self.dispatch_request()
File "/usr/lib/python2.7/dist-packages/flask/app.py", line 1461, in dispatch_request
return self.view_functionsrule.endpoint
File "/vagrant/web_server/webbyflask.py", line 18, in restaurantMenuJSON
return item.serialize
AttributeError: 'MenuItem' object has no attribute 'serialize'

this my webbyflask.py

from flask import Flask, render_template, request, url_for, redirect, flash, jsonify
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
from database_setup import Base, Restaurant, MenuItem
from flask.templating import render_template
app = Flask(__name__)


engine = create_engine('sqlite:///restaurantmenu.db')
Base.metadata.bind = engine

DBSession = sessionmaker(bind=engine)
session = DBSession()

@app.route('/restaurants/<int:restaurant_id>/menu/<int:menu_id>/JSON')
def restaurantMenuJSON(restaurant_id, menu_id):
    item = session.query(MenuItem).filter_by(id = menu_id).one()
    return item.serialize

and this is my database_setup.py

import sys
import os
from sqlalchemy import Column, ForeignKey, Integer, String
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import relationship
from sqlalchemy import create_engine

Base = declarative_base()

class Restaurant(Base):
    __tablename__ = 'restaurant'
    name = Column(String(80), nullable = False)
    id = Column(Integer, primary_key = True)

class MenuItem(Base):
    __tablename__ = 'menu_item'

    name = Column(String(80), nullable = False)
    id = Column(Integer, primary_key = True)
    course = Column(String(250))
    description = Column(String(250))
    price = Column(String(8))
    restaurant_id = Column(Integer, ForeignKey('restaurant.id'))
    restaurant = relationship(Restaurant)

    @property
    def serialize(self):
        return {
            'name': self.name,
            'description': self.description,
            'id': self.id,
            'price': self.price,
            'course': self.course,
        }

Hvuhionpm