I have been using flask for a while. I made an app implementing the application factory design pattern, but I can't understand the use of boo in the below-mentioned code.
from flask import Blueprint
some_blueprint = Blueprint("boo", __name__)
The first parameter of the Blueprint constructor (in your case boo) is simply a symbolic name that you assign to the Blueprint object.
Check out this link: https://flask.palletsprojects.com/en/2.0.x/tutorial/views/