What are Django validators and how do they work?

What are Django validators and how do they work?

Django validators are functions that validate data before it is saved to the database. They ensure that the data meets certain criteria.

Can you give me an example of a custom validator?

Sure! A custom validator can check if a username is at least 5 characters long. You can define it like this: def validate_username(value): if len(value) < 5: raise ValidationError('Username must be at least 5 characters long.').

How do I apply this validator to a model field?

You can apply it by using the validators argument in your model field. For example: username = models.CharField(max_length=150, validators=[validate_username]).

What built-in validators does Django provide?

Django provides several built-in validators like MaxLengthValidator, MinLengthValidator, and EmailValidator that you can use directly.