login_required decorator in Flask

I have 2 Flask apps (different projects) that work together . One implements some API which uses tokens for auth. The second one consumes the API and makes a web interface for it. Now I have a login function that sends the username and password to the API, and if correct, gets the auth token in return. Once I have the token, I save it to the session of the user and the user should now be considered as logged in/ autheticated.

Here is my login function -

def login(self):
        response = make_request(BASE_URL + 'login/', clean_data(self.data))
        if response.status_code == 200:
            session['auth_token'] = response.json().get('auth_token')
            return True
        return False

Also I am using Redis to store sessions if that matters. I have made the following login_required decorator -

def login_required(f):
    @wraps(f)
    def decorated_function(*args, **kwargs):
        if session.get('auth_token') is None:
            return redirect(url_for('login', next=request.url))
        return f(*args, **kwargs)

    return decorated_function

While it does work, I'm not sure if this is the best way to make that decorator. Any suggestions would be helpful.

I would suggest using:

if 'auth_token' not in session:
    ...

Since your login function suggests that auth_token is not a key in session, unless the user has logged in.

Other that that, I can see no other improvements.

StackExchange Code Review Q#115272, answer score: 2