Python 3 – PythonFlaskのセッションデータ

session['username'] = 'admin'

session.pop('username', None)

@app.route("https://pythonbasics.org/")
def index():
   if 'username' in session:
      username = session['username']
         return 'Logged in as ' + username + '<br>' + "<b><a href="https://pythonbasics.org/logout">click here to log out</a></b>"
   return "You are not logged in <br><a href="https://pythonbasics.org/login">" + "click here to log in</a>"

@app.route("https://pythonbasics.org/login", methods = ['GET', 'POST'])
def login():
   if request.method == 'POST':
      session['username'] = request.form['username']
      return redirect(url_for('index'))
   return '''
	
   <form action = "" method = "post">
      <p><input type = text name = username/></p>
      <p<<input type = submit value = Login/></p>
   </form>	
'''

The application also contains a logout () view function that pops up the 'username' session variable.Therefore, the "https://pythonbasics.org/" URL displays the start page again.

```python
@app.route("https://pythonbasics.org/logout")
def logout():
   
   session.pop('username', None)
   return redirect(url_for('index'))

from flask import Flask, session, redirect, url_for, escape, request
app = Flask(__name__)
app.secret_key = 'any random string’