Login and Logout in a Flask App

If you created your Flask Web App following the wiki tutorials, and you downloaded the zip file and extracted it into the 'site-packages' folder you will already have 'flask-wtf' installed and ready to go. If not then you need to install 'flask-wtf' using pip.

Setting Secret Key

You need to find the 'py' file which includes this code:

from flask import Flask
app = Flask(__name__)

And add the following to set the secret key:

app.config['SECRET_KEY'] = 'secret key'

Create forms.py

In the root folder of your project, create a new file called 'forms.py'.

Now add the following code:

from flask_wtf import FlaskForm
from wtforms import StringField, PasswordField, SubmitField
from wtforms.validators import DataRequired

class LoginForm(FlaskForm):
    username = StringField('Username', validators=[DataRequired()])
    password = PasswordField('Password', validators=[DataRequired()])
    submit = SubmitField('Sign In')

This will import the required modules to create a login form. The LoginForm class contains the fields to display on the form. It its important to note the 'DataRequired' validators.