What are some examples of validation in Django?

What are some examples of validation in Django?

Django provides various validation methods, such as field validators, model clean methods, and form validation. Would you like examples of each?

Yes, please provide examples for field validators.

Sure! For instance, you can use MaxLengthValidator to limit the length of a CharField. Here's an example:

from django.core.validators import MaxLengthValidator
from django.db import models

class MyModel(models.Model):
    my_field = models.CharField(max_length=100, validators=[MaxLengthValidator(50)])

This will ensure that my_field cannot exceed 50 characters.

What about model clean methods?

In a model's clean method, you can add custom validation logic. For example:

from django.core.exceptions import ValidationError

class MyModel(models.Model):
    my_field = models.IntegerField()

    def clean(self):
        if self.my_field < 0:
            raise ValidationError('my_field must be non-negative.')

This will raise a validation error if my_field is negative.