Example
First, ensure you have imported sessions from flask
from flask import session
To use session, a Flask application needs a defined SECRET_KEY.
app = Flask(__name__)
app.secret_key = 'app secret key'
Sessions are implemented by default using a cookie signed with the secret key. This ensures that the data is not modified except by your application, so make sure to pick a secure one! A browser will send the cookie back to your application along with each request, enabling the persistence of data across requests.
To use a session you just reference the object (It will behave like a dictionary)
@app.route('/')
def index():
if 'counter' in session:
session['counter'] += 1
else:
session['counter'] = 1
return 'Counter: '+str(session['counter'])
To release a session variable use pop() method.
session.pop('counter', None)
Example Code:
from flask import Flask, session
app = Flask(__name__)
app.secret_key = 'app secret key'
@app.route('/')
def index():
if 'counter' in session:
session['counter'] += 1
else:
session['counter'] = 1
return 'Counter: '+str(session['counter'])
if __name__ == '__main__':
app.debug = True
app.run()
