问Django CharField限制

EN

class BlackListModel(models.Model):   
   blacklist = ['a', 'b', 'c']

   # your model fields definitions...

   def save(self, *args, **kwargs):
        if self.blacklist_field in self.blacklist:
            raise Exception("Attempting to save a blacklisted value!")
        return super(BlackListModel, self).save(*args, **kwargs)

from django.db import models    
from django.core.exceptions import ValidationError

def validate_blacklist(value):
    if value in ['a', 'b', 'c']:
        raise ValidationError(
            "'a', 'b' and 'c' are prohibited!",
            params={'value': value},
        )

class MyModel(models.Model):
    even_field = models.CharField(max_length=200, validators=[validate_even])