Setting up Flask SQLAlchemy with PostgreSQL

Add these packages to your requirements.txt:

flask
Flask-SQLAlchemy
psycopg2-binary

Then install them from your terminal

pip install -r requirements.txt

In main.py:

from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_cors import CORS

# database connection parameters
DB_HOST = 'localhost'
DB_PORT = 5432
DB_USER = 'me'
DB_PASSWORD = 'password'
DB_DATABASE = 'mydb'

app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = f"postgresql://{DB_USER}:{DB_PASSWORD}@{DB_HOST}:{DB_PORT}/{DB_DATABASE}"
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
db = SQLAlchemy(app)

class Person(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(), nullable=False)
		
		# this function lets you convert an instance of this class into a dictionary
    def as_dict(self):
        return {c.name: getattr(self, c.name) for c in self.__table__.columns}

@app.route('/', methods=['GET'])
def index():
    return 'Hello world!'

if __name__ == '__main__':
    with app.app_context():
        db.create_all() # create tables
    app.run(port=8000, host='0.0.0.0')

Finally, run app with python main.py