What are the best practices for validation in Django?

What are the best practices for validation in Django?

Some best practices for validation in Django include using built-in validators, creating custom validators, and leveraging model field options.

Can you give me an example of a custom validator?

Sure! You can create a custom validator by defining a function that raises a ValidationError if the input is invalid. For example:

from django.core.exceptions import ValidationError

def validate_positive(value):
    if value <= 0:
        raise ValidationError('Value must be positive.')

How do I apply this custom validator to a model field?

You can apply the custom validator by adding it to the validators list of a model field like this:

from django.db import models

class MyModel(models.Model):
    my_field = models.IntegerField(validators=[validate_positive])

What about form validation? Are there best practices for that?

Yes! For form validation, use Django's built-in form classes, override the clean method for custom validation, and ensure to provide user-friendly error messages.