How to create generic modelform field validator for inherited model attributes in django?

Question

I have a parent model:

class AbstractAddress(models.Model):
    name = models.CharField(max_length=100,verbose_name='Name')
    address1 = models.CharField(max_length=100,null=True,blank=True)
    city = models.CharField(max_length=100,null=True,blank=True)
    phone = models.CharField(max_length=10,null=True,blank=True)
    pincode = models.IntegerField(null=True,blank=True, default=0)

    class Meta:
          abstract = True

This model I am inheriting to create Vendor, Client, Employee models. Now in admin ModelForm:

pincode = CharField(widget=TextInput(attrs={'type':'number'}),
                    validators=[RegexValidator(regex='^.{6}$',message='Pincode can have 6 digits')],
                    required=False, min_length=6)

phone = CharField(widget=TextInput(attrs={'type':'number',
                                          'size':'10'}),
                  validators=[RegexValidator(regex='^.{10}$', message='Phone can have 10 digits')],
                  required=False, min_length=10)

This code I do not want to write for every modelform for the above mentioned models. How can I use DRY for the same?

Answer 1

I have defined the validation in the project in the same folder as the settings.py and defined the validations methods as:

def validated_pincode():
    pincode = CharField(widget=TextInput(attrs={'type':'number'}),
                  validators=[RegexValidator(regex='^.{6}$',message='Pincode can have 6 digits')],
                    required=False, min_length=6)
    return pincode

in the modeladmin form I call the method:

pincode = validated_pincode()