docs: def to_python(self, value):
          """
          Convert the input JSON value into python structures, raises
          django.core.exceptions.ValidationError if the data can't be converted.
          """
          if self.blank and not value:
              return {}
          value = value or '{}'
          if isinstance(value, six.binary_type):
              value = six.text_type(value, 'utf-8')
          if isinstance(value, six.string_types):
              try:
                  # with django 1.6 i have '"{}"' as default value here
                  if value[0] == value[-1] == '"':
                      value = value[1:-1]
  
                  return json.loads(value)
              except Exception as err:
                  raise ValidationError(str(err))
          else:
              return value