Trabalhando com um banco de dados no Flask: de junho a junho

microblog\
  venv\
  app\
    __init__.py
    models.py
  main.py

from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_migrate import Migrate
from config import Config

app = Flask(__name__)
app.config.from_object(Config)
db = SQLAlchemy(app)
migrate = Migrate(app, db)

from datetime import datetime
from app import db

class Users(db.Model):
    #   
    __tablename__ = 'users'
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(120), index=True, unique=True)
    last_name = db.Column(db.String(128))
    first_name = db.Column(db.String(128))
    created = db.Column(db.DateTime, default=datetime.now())
    tasks = db.relationship('Tasks', backref='tasks')

    #     
    # def __init__(self, *args, **kwargs):
    #     super(Users, self).__init__(*args, **kwargs)

    def __init__(self, username, last_name, first_name):
        self.username = username
        self.last_name = last_name
        self.first_name = first_name

    def __repr__(self):
        return '<User {}>'.format(self.username)


class Tasks(db.Model):
    #    
    __tablename__ = 'tasks'
    id = db.Column(db.Integer, primary_key=True)
    owner_id = db.Column(db.Integer(), db.ForeignKey('users.id'))
    name = db.Column(db.String(120), index=True)
    start = db.Column(db.Boolean, default=False)
    finish = db.Column(db.Boolean, default=False)
    created_on = db.Column(db.DateTime, default=datetime.now())
    updated_on = db.Column(db.DateTime(), default=datetime.utcnow, onupdate=datetime.utcnow)

    #     
    def __init__(self, *args, **kwargs):
        super(Tasks, self).__init__(*args, **kwargs)

    # def __init__(self, name, last_name, first_name):
    #     self.name = name
    #     self.last_name = last_name
    #     self.first_name = first_name

    def __repr__(self):
        return '<Tasks {}>'.format(self.name)

import os
from dotenv import load_dotenv
load_dotenv()

basedir = os.path.abspath(os.path.dirname(__file__))


#    
class Config(object):
    DEBUG = True
    SECRET_KEY = os.environ.get('SECRET_KEY') or 'you-will-never-guess'
    # SQLALCHEMY_DATABASE_URI = 'postgresql+psycopg2://{user}:{pw}@{url}/{db}'.format(user=os.environ.get('POSTGRES_USER'),
    #                                                                                 pw=os.environ.get('POSTGRES_PW'),
    #                                                                                 url=os.environ.get('POSTGRES_URL'),
    #
    #                                                                                 db=os.environ.get('POSTGRES_DB'))
    SQLALCHEMY_DATABASE_URI = (os.environ.get('DATABASE_URL') or
                               'sqlite:///' + os.path.join(basedir, 'app.sqlite')) + '?check_same_thread=False'
    SQLALCHEMY_TRACK_MODIFICATIONS = False  # silence the deprecation warning

try:
    find_user_in_db(username, first_name, last_name)
except NameError:
    print("user  ")
except:
    print("An exception occurred")

def add_users_to_db(username, last_name, first_name):
    """
        
    :return:
    """
    data = Users(username, last_name, first_name)
    db.session.add(data)
    db.session.commit()

def find_user_in_db(username, first_name, last_name):
    """
               
    :param username:
    :param first_name:
    :param last_name:
    :return:
    """
    user = db.session.query(Users).filter(Users.username == f'{username}').all()
    if not user:
        add_users_to_db(username, first_name, last_name)