[Python] Flask "TemplateNotFound" Error for index.html Despite Correct Folder Structure

I am building a web application using Flask for a school project. However, I’m encountering a recurring issue where Flask cannot find the index.html template. I’ve verified that the folder structure is correct, and the templates are in the appropriate folder.

Here’s my folder structure:

oshinosensei/
├── static/
│ ├── Lorem.jpg
│ ├── Ipsum.jpg
│ ├── ...
├── templates/
│ ├── index.html
│ ├── result.html
└── app.py


Despite the correct setup, Flask is unable to find the index.html template when I try to run the app. After running python app.py, the server starts successfully, but the page fails to load due to this error:

jinja2.exceptions.TemplateNotFound: index.html


I have confirmed that index.html is in the templates folder, and I’ve printed the current working directory in my app.py file:

import os
print("Current working directory:", os.getcwd())


The output confirms that the working directory is correct:

Current working directory: C:\Users\남경천\oshinosensei


import os
from flask import Flask, render_template, request

app = Flask(__name__, template_folder='templates')

@app.route("/")
def index():
return render_template("index.html")

if __name__ == "__main__":
app.run(debug=True)


I’ve also tried adding the template_folder='templates' argument when initializing Flask, but the error persists.

Any help or suggestions on how to resolve this issue would be greatly appreciated!

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