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pythonlinuxflaskflask-session

'Flask' object has no attribute 'session_cookie_name'

I keep getting the error 'Flask' object has no attribute 'session_cookie_name' right at initialization on an app that used to work.

I built a smaller test app to test it and noticed that if I remove the line app.config["SESSION_TYPE"] = "filesystem" the error goes away. Problem is I need to use sessions in my Flask app and, since it is for testing, I would prefer to use the filesystem to store session data. here is my mini program for testing... I don't know what I am missing, this used to work fine and code examples online do it exactly this way but I keep getting the same error.

This is the error I receive

from flask import Flask, render_template,redirect, url_for, request, session
from flask_session import Session

app = Flask(__name__)

app.config["SESSION_PERMANENT"] = False
app.config["SESSION_TYPE"] = "filesystem"

Session(app)

@app.route("/")
def index():
    session["test"] = "test"
    return render_template ('index.html')

This worked before. It is all of the sudden not working. I have tried installing a different version of Flask_Session. I have tried adding the "SESSION_COOKIE_NAME" to app.config before Session(app) even though I understand its default is session. Nothing so far has worked or changed the error message.

Solution

  • This error happens when the currently used version of Flask does not have the session_cookie_name attribute. This attribute was added in Flask 2.0, so if you are using an older version of Flask, you will need to upgrade to a newer version.

    Just upgrade Flask by executing the command pip install --upgrade Flask

    Note: If you are using a virtual environment, be sure to activate it before upgrading.