def to_python(self, value):
        if not value:
            return None

        if isinstance(value, IPNetwork):
            network = value

        try:
            network = IPNetwork(value)
        except (AddrFormatError, TypeError, ValueError) as e:
            raise ValidationError(str(e))

        # Check for bits to the right of mask
        validate_ipnetwork(network)

        return network
 def to_python(self, value):
     value = super(CidrAddressField, self).to_python(value)
     # Check for bits to the right of mask
     validate_ipnetwork(value)
     return value