Sessions & Cookies – Flask Tutorial Series #6

In this tutorial, we will discuss sessions and cookies in Flask. Sessions and cookies are used to store data on the client side for maintaining the state of the application.

Sessions

Sessions are used to store user data across multiple requests. In Flask, sessions are implemented using the `session` object. You can set session variables using `session[‘key’] = value` and access them using `session.get(‘key’)`.

Here is an example of how to use sessions in Flask:

from flask import Flask, session

app = Flask(__name)
app.secret_key = 'secret_key'

@app.route('/')
def index():
    session['username'] = 'john'
    return 'Session variable set'

@app.route('/get')
def get():
    return 'Username is: ' + session.get('username')

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

Cookies

Cookies are small pieces of data stored on the client side. They are used to store information such as user preferences, shopping cart items, etc. In Flask, cookies can be set using the `set_cookie` method and accessed using the `request.cookies` object.

Here is an example of how to use cookies in Flask:

from flask import Flask, request

app = Flask(__name)

@app.route('/')
def index():
    resp = make_response('Cookie set')
    resp.set_cookie('username', 'john')
    return resp

@app.route('/get')
def get():
    username = request.cookies.get('username')
    return 'Username is: ' + username

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

Conclusion

Sessions and cookies are important tools for maintaining the state of an application in Flask. By using sessions and cookies, you can store user data and personalize the user experience. Make sure to keep sensitive information secure by using secure cookies and session management best practices.