Flask: ImportError: attempted relative import with no known parent package

Question

I really tried to solve this error with google, but could not find a solution that works. Maybe one of you has an idea.

My structure is this:

app/
 |- static/
 |    |- js/
 |    `- styles/
 |- templates/
 |- app.py
 |- auth.py
 |- db.sqlite
 |- main.py
 |- models.py
 `- requirements.txt

app.py:

from flask import Flask
from flask_sqlalchemy import SQLAlchemy

db = SQLAlchemy()

def create_app():

    app = Flask(__name__)

    app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///db.sqlite'
    app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False

    db.init_app(app)
    return app

app = create_app()

models.py:

from flask_login import UserMixin
from . import db

class User(UserMixin, db.Model):
    id = db.Column(db.Integer, primary_key=True)
    fname = db.Column(db.String(100))
    lname = db.Column(db.String(100))
    email = db.Column(db.String(100), unique=True)
    password = db.Column(db.String(100))

As an error i got this one:

File "C:\path\Flask_app\app\models.py", line 2, in <module>
    from . import db
ImportError: attempted relative import with no known parent package

I dont know what to change. In main.py i got a notice:

"db" is not accessed

Answer 1

You are missing an __init__.py to mark your project as a proper python package:

.
??? app
?   ??? app.py
?   ??? auth.py
?   ??? db.sqlite
?   ??? __init__.py
?   ??? main.py
?   ??? models.py
?   ??? static
?   ?   ??? js
?   ?   ??? styles
?   ??? templates
??? requirements.txt

works with python -m app.app or python app/app.py from the project root. But still, you likely want a setup.py or a pyproject.toml, e.g. to actually specify that you want to distribute your static/ files (and from the looks of it a sqlite-database?) with your package.