Flask and flask.g

The Flask framework is a popular framework in the Python programming language that allows us to easily create websites and APIs. In version 0.0, this framework has undergone changes and improvements, one of which is the addition of the new feature flask.g. This module provides us with the ability to access global information and variable sessions.

In fact, flask.g is a global object for each HTTP request. This means you can store specific information during request processing and access them at various points in the program. This feature is very useful because it helps you access information you need in a structured and organized way.

For example, if you want to store a user in an ongoing request session, using flask.g makes it easy to do this. The only thing you need to do is to store the user in flask.g and then access it in other routes or classes that require it.

However, a note to consider is that flask.g is only valid during the lifetime of a single HTTP request. This means if you send a request and receive a response, the next time will not have access to the stored information in flask.g. Therefore, to preserve information persistently, it is necessary to use other methods like storing data in the database.

Code Example

from flask import Flask, g

app = Flask(__name__)

@app.before_request
def before_request():
    g.user = "current user"

@app.route("/")
def index():
    return f"Hello, {g.user}!"

if __name__ == '__main__':
    app.run()

Code Explanation