Flask uses the MVC (Model View Controller) Framework. Just to make this as obvious as possible, I like my Flask apps to have the following.

• Model -> models.py
• View -> views.py
• Controller -> __init__.py

Let's say your Flask application has the following structure. Notice in this example there is a properties.txt file.

├── main.py
├── database (directory)
│   ├── example.db
├── my-project (directory)
│   ├── __init__.py
│   ├── views.py
│   ├── models.py
│   ├── templates (directory)
│   │   ├── base.html
│   │   ├── home.html
│   │   ├── results.html
│   └── static (directory)
│       └── custom.css
│       └── properties.txt

Let's say properties.txt contains key value pairs.

ip=127.0.0.1

In your view (views.py in this example), here is how you could store the value of each value. In this example, the "ip" variable should contain the value in the properties.txt file (127.0.0.1).

import os
from flask import Blueprint, render_template

views = Blueprint('views', __name__)

@views.route('/')
def home():
    basedir = os.path.abspath(os.path.dirname(__file__))
    prop_file = os.path.join(basedir, 'static/files/properties.txt')

    if os.path.exists(prop_file ) == False:
        print(f"{json_file} does NOT exist")
        flash('Sorry. Something got totally hosed up on my end. Try again?', category='danger')
        return render_template('mybad.html')

    if os.path.isfile(prop_file ) == False:
        print(f"{prop_file} is NOT a file")
        flash('Sorry. Something got totally hosed up on my end. Try again?', category='danger')
        return render_template('mybad.html')

    if os.access(prop_file , os.R_OK) == False:
        print(f"{prop_file is NOT readable")
        flash('Sorry. Something got totally hosed up on my end. Try again?', category='danger')
        return render_template('mybad.html')

    with open(prop_file, "r") as file:
        for line in file.readlines():
            if "ip" in line:
                line = re.sub("ip=", "", line)
                ip = line.strip()
                print("IP = " + ip)

    return render_template('home.html')