old_contents: from netaddr import EUI, mac_unix_expanded
  
  from django.core.exceptions import ValidationError
  from django.db import models
  
  from .formfields import MACAddressFormField
  
  class mac_unix_expanded_uppercase(mac_unix_expanded):
      word_fmt = '%.2X'
  
  
  class MACAddressField(models.Field):
      description = "PostgreSQL MAC Address field"
  
      def python_type(self):
          return EUI
  
      def from_db_value(self, value, expression, connection, context):
          return self.to_python(value)
  
      def to_python(self, value):
          if not value:
              return value
          try:
              return EUI(value, dialect=mac_unix_expanded_uppercase)
          except ValueError as e:
              raise ValidationError(e)
  
      def db_type(self, connection):
          return 'macaddr'
  
      def get_prep_value(self, value):
          if not value:
              return None
          return str(self.to_python(value))
  
      def form_class(self):
          return MACAddressFormField
  
      def formfield(self, **kwargs):
          defaults = {'form_class': self.form_class()}
          defaults.update(kwargs)
          return super(MACAddressField, self).formfield(**defaults)
  
new_contents: from netaddr import EUI, mac_unix_expanded
  
  from django.core.exceptions import ValidationError
  from django.db import models
  
  from .formfields import MACAddressFormField
  
  
  class mac_unix_expanded_uppercase(mac_unix_expanded):
      word_fmt = '%.2X'
  
  class MACAddressField(models.Field):
      description = "PostgreSQL MAC Address field"
  
      def python_type(self):
          return EUI
  
      def from_db_value(self, value, expression, connection, context):
          return self.to_python(value)
  
      def to_python(self, value):
          if not value:
              return value
          try:
              return EUI(value, dialect=mac_unix_expanded_uppercase)
          except ValueError as e:
              raise ValidationError(e)
  
      def db_type(self, connection):
          return 'macaddr'
  
      def get_prep_value(self, value):
          if not value:
              return None
          return str(self.to_python(value))
  
      def form_class(self):
          return MACAddressFormField
  
      def formfield(self, **kwargs):
          defaults = {'form_class': self.form_class()}
          defaults.update(kwargs)
          return super(MACAddressField, self).formfield(**defaults)
  
subject: Fix PEP8 compliance...