Develop Reference

Python Flask create schedule on startup

I am new-ish to python and new to Flask. I am trying to use APScheduler to schedule a db update when the app starts. It works until I tried to update the database. It says the database is not defined, but I am importing with from .models import Readings. Error can be recreated by uncommenting the lines in interval_task().
init.py
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_apscheduler import APScheduler
from os import path
from flask_login import LoginManager
import pandas as pd
import multiprocessing
import random
db = SQLAlchemy()
DB_NAME_LEOTTA = "leotta.db"
DB_NAME_QUICK = "quick.db"
simulated_room_temperature = multiprocessing.Value('d', 29)
def create_app():
app = Flask(__name__)
app.config['SECRET_KEY'] = '0ddish'
app.config['SQLALCHEMY_DATABASE_URI'] = f'sqlite:///databases/{DB_NAME_LEOTTA}'
app.config['SQLALCHEMY_BINDS'] = {'quickdb' : f'sqlite:///databases/{DB_NAME_QUICK}'}
db.init_app(app)
from .views import views
from .auth import auth
from .scheduler import scheduler
app.register_blueprint(views, url_prefix='/')
app.register_blueprint(auth, url_prefix='/')
app.register_blueprint(scheduler, url_prefix='/')
from .models import User, Note, Readings
create_database(app)
sched = APScheduler()
sched.init_app(app)
sched.start()
INTERVAL_TASK_ID = '1'
sched.add_job(id=INTERVAL_TASK_ID, func=interval_task, trigger='interval', seconds=5)
login_manager = LoginManager()
login_manager.login_view = 'auth.login'
login_manager.init_app(app)
#login_manager.user_loader
def load_user(id):
return User.query.get(int(id))
return app
def create_database(app):
if not path.exists('website/databases/' + DB_NAME_LEOTTA):
#since no bind is specified, it will use default bind
db.create_all(app=app)
print('Created Database ' + DB_NAME_LEOTTA)
if not path.exists('website/databases/' + DB_NAME_QUICK):
db.create_all(bind=DB_NAME_QUICK)
print('Created Database ' + DB_NAME_QUICK)
def interval_task():
simulated_room_temperature.value = random.uniform(19, 31)
#reading = Readings(param_name='Temperature', param_value=simulated_room_temperature.value)
#db.session.add(reading)
#db.session.commit()
print(random.uniform(19, 31))
main.py
from website import create_app
app = create_app()
if __name__ == '__main__':
app.run(debug=True)
models.py
from . import db
from flask_login import UserMixin
from sqlalchemy.sql import func
class Note(db.Model):
#no bind specified, will use default
id = db.Column(db.Integer, primary_key=True)
note = db.Column(db.String(150))
date_time = db.Column(db.DateTime(timezone=True), default=func.now('UTC'))
user_id = db.Column(db.Integer, db.ForeignKey('user.id'))
class User(db.Model, UserMixin):
#no bind specified, will use default
id = db.Column(db.Integer, primary_key=True)
email = db.Column(db.String(150), unique=True)
password = db.Column(db.String(150))
first_name = db.Column(db.String(150))
notes = db.relationship('Note')
class Readings(db.Model):
__bind_key__ = 'quickdb'
id = db.Column(db.Integer, primary_key=True)
param_name = db.Column(db.String(150), unique=True)
date_time = db.Column(db.DateTime(timezone=True), default=func.now('UTC'))
param_value = db.Column(db.Float)

Flask-Marshmallow returning empty json and saying my schema is invalid

I am trying to use Marshmallow to serialize my Message Model class yet it is returning an empty json object whenever I try to get the data and after I debugged the program with
print(messagesSchema.validate(messages))
It said: 0: {'_schema': ['Invalid input type.']}
This is my Chat model, Message Model and my MessageSchema model
class Chat(db.Model):
id = db.Column(db.Integer, primary_key=True)
user1 = db.Column(db.String(150), unique=True)
user2 = db.Column(db.String(150), unique=True)
room = db.Column(db.String(300), unique=True)
messages = db.relationship("Message", backref="chat")
class Message(db.Model):
id = db.Column(db.Integer, primary_key=True)
text = db.Column(db.String(300))
username = db.Column(db.String(150))
chat_id = db.Column(db.Integer, db.ForeignKey("chat.id"))
class MessageSchema(ma.SQLAlchemySchema):
class Meta:
model = Message
This is my socketHandler file
messages = Chat.query.filter_by(room=room).first().messages
messagesSchema = MessageSchema(many=True)
print(messagesSchema.validate(messages))
output = messagesSchema.dump(messages)
print(output)
print(jsonify(output))
and the init.py file if anybody is wondering
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_marshmallow import Marshmallow
from os import path
from flask_login import LoginManager
db = SQLAlchemy()
DB_NAME = "database.db"
ma = Marshmallow()
def create_app():
app = Flask(__name__)
app.config["SECRET_KEY"] = "secret"
app.config["SQLALCHEMY_DATABASE_URI"] = f'sqlite:///{DB_NAME}'
db.init_app(app)
from .views import views
from .auth import auth
from .slashUrl import slashUrl
app.register_blueprint(slashUrl, url_prefix="/")
app.register_blueprint(views, url_prefix="/home/")
app.register_blueprint(auth, url_prefix="/auth/")
from .models import User
create_database(app)
login_manager = LoginManager()
login_manager.login_view = "auth.login"
login_manager.login_message_category = "dangerAlert"
login_manager.init_app(app)
#login_manager.user_loader
def load_user(id):
return User.query.get(int(id))
return app
def create_database(app):
if not path.exists("website/" + DB_NAME):
db.create_all(app=app)
print("Database created")
From my print statements I get
{0: {'_schema': ['Invalid input type.']}}
[{}]
<Response 9 bytes [200 OK]>
If anybody knows how to fix this your help would be greatly appreciated!

Flask-sqlalchemy AttributeError: 'function' object has no attribute 'query'

I've been using flask with flask-sqlalchemy successfully for a number of weeks, but all of a sudden my code is coming up with this error: AttributeError: 'function' object has no attribute 'query', relating to this line of code:
project_choices = [(str(c.id) + ': ' + c.project_name) for c in Projects.query.all()]
Seems like the flask-sqalchemy Projects class is not being successfully created but I can't work out why.
Main routes file:
from flask import Flask, request, flash, url_for, redirect, render_template, session
from flask_sqlalchemy import SQLAlchemy
from app import db
from app import app
from app.forms import Basic_data_Form, Which_project#, Areas_form
from flask_bootstrap import Bootstrap
from app.models import Projects
#app.route('/Index', methods = ['GET', 'POST'])
def Index():
if 'project_name' not in session:
session['project_name'] = "0: No project selected"
project_name = session['project_name'].split(':')[1]
project_choices = [(str(c.id) + ': ' + c.project_name) for c in Projects.query.all()]
form2 = Which_project()
form2.project_choice.choices = project_choices
return render_template('Index.html', form2=form2, projects = Projects.query.filter_by(id=session['project_name'].split(':')[0]).all(), project_name=project_name)
init file:
from flask import Flask
from config import Config
from flask_sqlalchemy import SQLAlchemy
from flask_bootstrap import Bootstrap
app = Flask(__name__)
app.config.from_object(Config)
db = SQLAlchemy(app)
bootstrap = Bootstrap(app)
from app import routes
models file:
from app import db
class Projects(db.Model):
id = db.Column(db.Integer, primary_key=True, autoincrement=True)
project_name = db.Column(db.String(100))
user_id = db.Column(db.String(100))
address = db.Column(db.String(100))
region = db.Column(db.String(100))
postcode = db.Column(db.String(20))
building_year = db.Column(db.Integer)
climate_file = db.Column(db.String(100))
building_TFA = db.Column(db.Float)
thermal_mass = db.Column(db.String(100))
winter_int_temp = db.Column(db.Float)
summer_int_temp = db.Column(db.Float)
height_above_sea = db.Column(db.Float)
occupany = db.Column(db.Float)
def __repr__(self):
return '<Project {}>'.format(self.project_name)

I had a similar issue with that same error. It was because there was a function with the same name. So that is probably why it was saying a function had no attribute query even though the table used with sqlalchemy is a class

Consider either implementing a class function which renders the object into the current string representation you desire or implementing a hybrid property.
String method:
class Projects(db.Model):
...
id = db.Column(db.Integer, primary_key=True, autoincrement=True)
project_name = db.Column(db.String(100))
...
def __str__(self):
return f'{self.id}: {self.project_name}'
Use string method as follows:
project_choices = Projects.query.all()
form2 = Which_project()
# probably str(x) would work, but if it doesn't the code below def works
form2.project_choice.choices = [x.__str__() for x in project_choices]
Hybrid property method:
from sqlalchemy.ext.hybrid import hybrid_property, hybrid_method
class Projects(db.Model):
...
id = db.Column(db.Integer, primary_key=True, autoincrement=True)
project_name = db.Column(db.String(100))
...
#hybrid_property
def project_choice(self):
return f'{self.id}: {self.project_name}'
Use hybrid property as follows:
# Access only the hybrid property
project_choices = Projects.query(Projects.project_choice).all()
form2 = Which_project()
form2.project_choice.choices = project_choices

Python flask SqlAlchemy: Data is getting stored in different table other than specified

I am facing issue while inserting Data in the different Tables using Python flask and SQLAlchemy
Issue :
When I insert the Data in "device_data" table it gets inserted in the other Table
"registration_data"
The Page also gets redirected the Registration Forms
The Code in my main.py file is as follows
{
import sqlite3 as sql
from flask import Flask, render_template
from flask import redirect, url_for, session, request, g
from flask_sqlalchemy import SQLAlchemy
import wtforms
from flask_wtf import Form
# from flask_user import roles_required
from wtforms import validators
app = Flask(__name__)
app.config['SECRET_KEY'] = 'a8b84f7b63d64fb2a6e0161caabc4673'
app.config['SQLALCHEMY_DATABASE_URI'] ='sqlite:///samlple.db'
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] =True
db = SQLAlchemy(app)
class RegistrationData(db.Model):
id= db.Column(db.Integer, primary_key=True)
Patient_Name = db.Column(db.String(80))
Patient_Age = db.Column(db.Integer)
email = db.Column(db.String(80))
Doctor_Name= db.Column(db.String(80))
PhoneNumber=db.Column(db.String(80))
Equipment=db.Column(db.String(80))
Deposit= db.Column(db.Integer)
Disease= db.Column(db.String(80))
Issue_Date= db.Column(db.String(80))
Return_Date= db.Column(db.String(80))
Address = db.Column (db.String (80))
def __init__(self,
Patient_Name,
Patient_Age,
email,
Doctor_Name,
PhoneNumber,
Equipment,
Deposit,
Disease,
Issue_Date,
Return_Date,
Address):
self.Patient_Name = Patient_Name
self.Patient_Age = Patient_Age
self.email = email
self.Doctor_Name = Doctor_Name
self.PhoneNumber = PhoneNumber
self.Equipment = Equipment
self.Deposit = Deposit
self.Disease = Disease
self.Issue_Date = Issue_Date
self.Return_Date = Return_Date
self.Address = Address
class DeviceData (db.Model):
id = db.Column (db.Integer, primary_key=True)
DeviceName = db.Column (db.String (80))
quantity = db.Column (db.Integer)
Price = db.Column (db.String (80))
Deposit = db.Column (db.String (80))
Location = db.Column (db.String (80))
description = db.Column (db.String (80))
#app.route('/')
def home():
return render_template("index.html")
#app.route('/template/device')
def devices():
return render_template("device.html")
#app.route('/templates/home')
def about():
name= "Rugna Sahayata Kendra"
return render_template("home.html", name=name)
#app.route('/templates/Registration')
def Registration():
name= "Rugna Sahayata Kendra"
return render_template("RegistrationForm.html", name=name)
#app.route('/templates/Add_Device')
def AddDevice():
name= "Rugna Sahayata Kendra"
return render_template("Add_Device.html", name=name)
#app.route ('/templates/table')
def AllocationList():
con = sql.connect ("samlple.db")
con.row_factory = sql.Row
cur = con.cursor ()
cur.execute ("select * from registration_data")
rows = cur.fetchall ();
return render_template ("table.html", rows=rows)
#app.route ('/templates/EquipmentList')
def EquipmentList():
con = sql.connect ("samlple.db")
con.row_factory = sql.Row
cur = con.cursor ()
cur.execute ("select * from device_data")
rows = cur.fetchall ();
return render_template ("EquipmentList.html", rows=rows)
#app.route("/home", methods=["GET", "POST"])
def register():
if request.method == "POST":
P_Name = request.form.get('PatientName')
P_AGE=request.form.get ('Age')
P_Email=request.form.get ('email')
D_Name=request.form.get ('DoctorName')
Phone_No=request.form.get ('phoneNumber')
equipment=request.form.get ('Equipment')
deposit=request.form.get ('Deposit')
disease=request.form.get('Disease')
I_Date=request.form.get ('IssueDate')
R_Date=request.form.get ('ReturnDate')
address = request.form.get('Address')
register = RegistrationData(Patient_Name=P_Name,
Patient_Age=P_AGE,
email=P_Email,
Doctor_Name=D_Name,
PhoneNumber=Phone_No,
Equipment=equipment,
Deposit=deposit,
Disease=disease,
Issue_Date=I_Date,
Return_Date=R_Date,
Address=address
)
db.session.add (register)
db.session.commit()
return render_template ("RegistrationForm.html")
#app.route("/home", methods=["GET", "POST"])
def AddDeviceDB():
if request.method == "POST":
D_Name = request.form.get('DeviceName')
Quantity=request.form.get ('Quantity')
Price=request.form.get ('Price')
Deposit=request.form.get ('Deposit')
Location=request.form.get ('Location')
Description=request.form.get ('Description')
deviceList = DeviceData(DeviceName=D_Name,
quantity=Quantity,
Price=Price,
Deposit=Deposit,
Location=Location,
description=Description
)
db.session.add(deviceList)
db.session.commit()
return render_template ("EquipmentList.html")
if __name__=='__main__':
app.run(debug=True)
}

<Object id> is not JSON serializable

i'm creating an API in python + Flask + marshmallow.
Here's the class + the first function (i don't already use the others )
import datetime
from marshmallow import Schema, fields, ValidationError, pre_load
from flask import Flask, jsonify
from flask_marshmallow import Marshmallow
from flask_sqlalchemy import SQLAlchemy
from flask import request
import os
app = Flask(__name__)
basedir = os.path.abspath(os.path.dirname(__file__))
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///' + os.path.join(basedir, 'User.sqlite')
# Order matters: Initialize SQLAlchemy before Marshmallow
db = SQLAlchemy(app)
ma = Marshmallow(app)
class User(db.Model):
userid = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String(30))
badgenum = db.Column(db.String(30))
mail = db.Column(db.String(30))
status = db.Column(db.String(30))
admin = db.Column(db.String(30))
def __init__(self, userid, name, badgenum, mail, status, admin):
self.userid = userid
self.name = name
self.badgenum = badgenum
self.mail = mail
self.status = status
self.admin = admin
class UserSchema(ma.Schema):
class Meta:
fields = ('userid', 'name', 'badgenum', 'mail', 'status', 'admin')
user_schema = UserSchema()
users_schema = UserSchema(many=True)
#app.route("/User", methods=["POST"])
def add_User():
userid = request.json['userid']
name = request.json['name']
badgenum = request.json['badgenum']
mail = request.json['mail']
status = request.json['status']
admin = request.json['admin']
new_user = User(userid, name, badgenum, mail, status, admin)
db.session.add(new_user)
db.session.commit()
return jsonify(new_user)
I tested the function add_User using Postman with this json request :
{
"userid" : 1,
"name" : "name1",
"badgenum" : "66897",
"mail" : "ghh#orange.fr",
"status" : "on",
"admin" : "f"
}
and i got this error:
TypeError: <User 145> is not JSON serializable

User has its own autogenerated id user.id which is ObjectId.
You need custom json encoder to encode ObjectId field.
import json, bson
def json_response(obj, cls=None):
response = make_response(json.dumps(obj, cls=cls))
response.content_type = 'application/json'
return response
class MongoJsonEncoder(json.JSONEncoder):
def default(self, obj):
if isinstance(obj, bson.ObjectId):
return str(obj)
return json.JSONEncoder.default(self, obj)
Now try to call return json_response(new_user, cls=MongoJsonEncoder)