Flask app returning 'NoneType' scenarios when trying to render template with dynamic data
I'm dealing with I've searched everywhere and can't find a clear answer... I'm working on a Flask application where I'm trying to render a template with some dynamic data fetched from a database. However, I'm working with a 'TypeError: 'NoneType' object is not subscriptable' behavior when I attempt to access the data in my template. I've confirmed that the database query is returning results, but it seems like the data isn't being passed correctly to the template. Here’s a simplified version of my route code: ```python from flask import Flask, render_template from models import User # assuming User is a SQLAlchemy model app = Flask(__name__) @app.route('/users/<int:user_id>') def get_user(user_id): user = User.query.get(user_id) return render_template('user_profile.html', user=user) ``` In my `user_profile.html`, I try to access the user's attributes like this: ```html <h1>{{ user.name }}</h1> <p>Email: {{ user.email }}</p> ``` If I directly print `user` in the route before the return statement, I see the correct User object. However, when I check the template, the rendered output shows nothing, and I get the NoneType behavior when I try to access 'name' or 'email'. I've ensured that the user ID exists in the database, but my debugging hasn’t revealed why this is happening. I also tried changing the query to: ```python user = User.query.filter_by(id=user_id).first() ``` but the result is the same. Does anyone have any insights into what might be causing this scenario, or what I'm missing in the data flow? I'm using Flask 2.1.0 and SQLAlchemy 1.4.22. I'm working on a service that needs to handle this. I'm developing on CentOS with Python. This issue appeared after updating to Python 3.11. Has anyone else encountered this?