How to use Flask-Session in Python Flask

To use Flask-Session in a Flask application in Python, you need to install the flask-session package using pip. You can then import the Session class from the flask_session module and use it to configure the session for your Flask application.

Here is an example of how to set up Flask-Session in a Flask application:

from flask import Flask, session
from flask_session import Session

app = Flask(__name__)
app.config["SESSION_PERMANENT"] = False
app.config["SESSION_TYPE"] = "filesystem"
Session(app)

@app.route("/")
def index():
    # Set session data
    session["name"] = "John"
    return "Session data set"

@app.route("/get")
def get():
    # Get session data
    name = session.get("name")
    return f"The name is {name}"

This code sets up a Flask application and initializes the Flask-Session extension by creating a Session object and passing in the Flask app object. The SESSION_PERMANENT configuration option sets whether the session should be permanent or not (default is False), and the SESSION_TYPE option sets where the session data should be stored on the server (in this case, in the file system).

In the index() function, it sets the value of the name key in the session dictionary using the session object. In the get() function, it retrieves the value of the name key from the session using the get() method, which returns None if the key is not in the dictionary.

When you run this code and navigate to the / route, it will set the session data to the value “John”. When you navigate to the /get route, it will retrieve the session data and display it in a message.

Note that you can also use other storage options for session data in Flask-Session, such as Redis or memcached. You can find more information on how to set up Flask-Session with other storage options in the Flask-Session documentation.

You can install Flask-Session using the pip command

You can install Flask-Session using the pip command. Open a command prompt or terminal window and type the following command:

pip install flask-session

This command downloads and installs the Flask-Session package along with its dependencies.

After the installation is complete, you can import and use the Session class from the flask_session module in your Flask application to set up session management. For example, you can create a Flask app object and initialize the Session class like this:

from flask import Flask
from flask_session import Session

app = Flask(__name__)
app.config['SESSION_TYPE'] = 'filesystem'
Session(app)

This code sets the SESSION_TYPE configuration option to filesystem, which stores session data in server-side files instead of in-memory. You can also configure other options such as SESSION_PERMANENT, SESSION_FILE_DIR, and SESSION_FILE_THRESHOLD as needed. Refer to the Flask-Session documentation for more information on available configuration options.