Cleaning forms

We can perform validation on form fields in other ways as well. Within a form class, we can write methods that validate each field individually by writing them in this format: def clean_{{ form_field_name }}(). When doing this, only the value of the field that we are cleaning can be accessed. If we want to access other field values found in that form, we have to write a single def clean() method that will allow us to compare two fields against each other. For example, we could use the def clean() method to only require a field when another field's value is not empty.

The following two subsections break down these two concepts.

Method – clean_{{ your_field_name }}()

To clean an individual form field, follow these steps:

1. In your /chapter_5/forms.py file, in the same ContactForm class, add a new field called email_3, as shown:

   # /becoming_a_django_entdev/chapter_5/forms.py
   from django 
   import forms
   from django.forms 
   import Form, ModelForm
   ...