What are WTForms built-in validators?

What are WTForms built-in validators?

WTForms provides several built-in validators that help ensure data integrity and validation in forms. These include validators like DataRequired, Email, Length, and more.

Can you give me an example of how to use the DataRequired validator?

Sure! You can use the DataRequired validator in your form field like this:

from wtforms import Form, StringField
from wtforms.validators import DataRequired

class MyForm(Form):
    name = StringField('Name', [DataRequired()])

What happens if the validation fails?

If validation fails, WTForms will raise a validation error, and you can access the errors through the form's errors attribute.

Are there any custom validators I can create?

Yes, you can create custom validators by defining a function that raises a ValidationError if the validation fails. You can then use it in your form fields.