ImportError: cannot import name

Question

I have two files app.py and mod_login.py

app.py

from flask import Flask from mod_login import mod_login  app = Flask(__name__) app.config.update(     USERNAME='admin',     PASSWORD='default' ) 

mod_login.py

# coding: utf8  from flask import Blueprint, render_template, redirect, session, url_for, request from functools import wraps from app import app  mod_login = Blueprint('mod_login', __name__, template_folder='templates') 

And python return this error:

Traceback (most recent call last):   File "app.py", line 2, in <module>     from mod_login import mod_login   File "mod_login.py", line 5, in <module>     from app import app   File "app.py", line 2, in <module>     from mod_login import mod_login ImportError: cannot import name mod_login 

If I delete from app import app, code will be work, but how I can get access to app.config?

Answer 1

The problem is that you have a circular import: in app.py

from mod_login import mod_login 

in mod_login.py

from app import app 

This is not permitted in Python. See Circular import dependency in Python for more info. In short, the solution are

• either gather everything in one big file
• delay one of the import using local import

Answer 2

This can also happen if you've been working on your scripts and functions and have been moving them around (i.e. changed the location of the definition) which could have accidentally created a looping reference.

You may find that the situation is solved if you just reset the iPython kernal to clear any old assignments:

%reset 

or menu->restart terminal