Email Validation in Python Flask

Email validation is an important aspect of web development, especially when it
comes to user authentication and sign-up processes. In this article, we will
explore how to perform email validation in Python Flask.

Why Email Validation is Important

Before we dive into the technical details of email validation in Flask, let’s
first understand why it is important.

Email validation is necessary to ensure that the email address provided by the
user is valid and belongs to them. This helps prevent spam, fake accounts, and
ensures that the user receives important notifications and updates from your
website or application.

Performing Email Validation in Python Flask

In Flask, email validation can be performed using various libraries and
modules. One popular library is the email-validator library.

First, install the email-validator library using pip:

pip install email-validator

Next, import the library in your Flask application:

from email_validator import validate_email, EmailNotValidError

Now, you can use the validate_email() function to check if an email address is
valid:

try:
# Validate an email address
valid = validate_email(email)
# Update the email address with the normalized form
email = valid.email
except EmailNotValidError as e:
# Handle an invalid email address
print(str(e))

The validate_email() function returns a ValidatedEmail object if the email
address is valid. This object contains the normalized form of the email
address, which can be used to update the user’s email address in your
database.

Integrating Email Validation with Flask-WTF

If you are using Flask-WTF for your forms and user authentication, you can
easily integrate email validation using the Email field type:

from flask_wtf import FlaskForm
from wtforms import StringField, PasswordField, BooleanField, SubmitField
from wtforms.validators import DataRequired, Email, EqualTo, ValidationError

class LoginForm(FlaskForm):
email = StringField('Email', validators=[DataRequired(), Email()])
password = PasswordField('Password', validators=[DataRequired()])
remember_me = BooleanField('Remember Me')
submit = SubmitField('Log In')

The Email() validator ensures that the email address provided by the user is
valid before submitting the form.

Conclusion

Email validation is an important aspect of web development, especially when it
comes to user authentication and sign-up processes. In this article, we
explored how to perform email validation in Python Flask, using the email-
validator library and Flask-WTF. By implementing email validation in your
Flask application, you can improve the security and reliability of your
website or application.