flask saying 'module "flaskr.db' has no attribute 'init_app' "

Question

I'm new to flask and i'm learning from the official tutorial, I just set up my sqlite db and templates. The problem is when i run flask run after setting venv and env variables. It gives me this error output -

P.S - flask-learn is my venv(ik its weird, ill set it to venv in future)

Traceback (most recent call last):
  File "C:\Users\Kakshipth\Documents\coding\py\backend\flask-learn\Lib\site-packages\flask\_compat.py", line 39, in reraise
    raise value
  File "C:\Users\Kakshipth\Documents\coding\py\backend\flask-learn\Lib\site-packages\flask\cli.py", line 83, in find_best_app
    app = call_factory(script_info, app_factory)
  File "C:\Users\Kakshipth\Documents\coding\py\backend\flask-learn\Lib\site-packages\flask\cli.py", line 119, in call_factory
    return app_factory()
  File "C:\Users\Kakshipth\Documents\coding\py\backend\flaskr\__init__.py", line 36, in create_app
    db.init_app(app)
AttributeError: module 'flaskr.db' has no attribute 'init_app'

I'm guessing the problem is with __init__.py or db.py modules, but i did exactly what the documentation said.And i'm running these scripts from backend folder(dir structure below)

I'm guessing you might as for directory structure so here it is -

backend
|
├───flaskr
│   ├───templates
│   │   └───auth
│   └───__pycache__
|
|___flask-learn

here is __init__.py -

import os

from flask import Flask


def create_app(test_config=None):
    # create and configure the app
    app = Flask(__name__, instance_relative_config=True)
    app.config.from_mapping(
        SECRET_KEY='dev',
        DATABASE=os.path.join(app.instance_path, 'flaskr.sqlite'),
    )

    if test_config is None:
        # load the instance config, if it exists, when not testing
        app.config.from_pyfile('config.py', silent=True)
    else:
        # load the test config if passed in
        app.config.from_mapping(test_config)

    # ensure the instance folder exists
    try:    
        os.makedirs(app.instance_path)
    except OSError:
        pass 

    from . import auth
    app.register_blueprint(auth.bp)

    # a simple page that says hello
    @app.route('/hello')
    def hello():
        return 'Hello, !'

    from . import db
    db.init_app(app)

    return app

Here is db.py -

import sqlite3

import click
from flask import current_app, g
from flask.cli import with_appcontext


def get_db():
    if 'db' not in g:
        g.db = sqlite3.connect(
            current_app.config['DATABASE'],
            detect_types=sqlite3.PARSE_DECLTYPES
        )
        g.db.row_factory = sqlite3.Row

    return g.db


def close_db(e=None):
    db = g.pop('db', None)

    if db is not None:
        db.close()

def init_db():
    db = get_db()

    with current_app.open_resource('schema.sql') as f:
        db.executescript(f.read().decode('utf8'))


@click.command('init-db')
@with_appcontext
def init_db_command():
    """Clear the existing data and create new tables."""
    init_db()
    click.echo('Initialized the database.')

link to the official documentation im following

Answer 1

Your db.py is missing the init_app-function:

def init_app(app):
    app.teardown_appcontext(close_db)
    app.cli.add_command(init_db_command)