raise exc.NoSuchModuleError( sqlalchemy.exc.NoSuchModuleError: Can't load plugin: sqlalchemy.dialects:postgresql

Question

I created a sample flask application, I want to connect PostgreSQL database to my project. I installed flask_sqlalchemy.

here is my Code

from flask import Flask, url_for, render_template
from flask_sqlalchemy import SQLAlchemy

app = Flask(__name__)

app.config['SQLALCHEMY_DATABASE_URI'] = 'postgresql://michealscott:dwight@localhost:5432/michealscott'
db = SQLAlchemy(app)

class User(db.Model):
    __tablename__ = 'books'
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(80), unique=True)
    email = db.Column(db.String(120), unique=True)

    def __init__(self, username, email):
        self.username = username
        self.email  = email



@app.route('/')
def hello_world():
    return render_template("index.html")

I cd-ed into my src directory and executed:

python
>> from app import db
>> db.create_all()

then the above error shows up.

After searching over internet. I also did

pip install psycopg2

still no luck.

there is a same question on stack overflow and couple of answers/suggestions. I was not able to comment on the post so asking it again pardon me!

Please help.

Thank you in advance.