How do I use the clean method in Django form extensions?

How do I use the clean method in Django form extensions?

The clean method in Django form extensions allows you to add custom validation logic to your forms. You can override it in your form class.

Can you give me an example of how to implement it?

Sure! You can define the clean method like this:

from django import forms

class MyForm(forms.Form):
    name = forms.CharField(max_length=100)

    def clean_name(self):
        name = self.cleaned_data.get('name')
        if not name.isalpha():
            raise forms.ValidationError('Name must contain only letters.')
        return name

What happens if the validation fails?

If the validation fails, a ValidationError is raised, and the form will not be valid. The error message will be displayed to the user.