          """
          try:
              return get_attribute(instance, self.source_attrs)
          except (KeyError, AttributeError) as exc:
              if self.default is not empty:
                  return self.get_default()
              if self.allow_null:
                  return None
 
</s> remove from rest_framework.fields import DjangoImageField, is_simple_callable
 </s> add from rest_framework.fields import (
    BuiltinSignatureError, DjangoImageField, is_simple_callable
)
        except BuiltinSignatureError as exc:
            msg = (
                'Field source for `{serializer}.{field}` maps to a built-in '
                'function type and is invalid. Define a property or method on '
                'the `{instance}` instance that wraps the call to the built-in '
                'function.'.format(
                    serializer=self.parent.__class__.__name__,
                    field=self.field_name,
                    instance=instance.__class__.__name__,
                )
            )
            raise type(exc)(msg)
          """
          try:
              return get_attribute(instance, self.source_attrs)
        except BuiltinSignatureError as exc:
            msg = (
                'Field source for `{serializer}.{field}` maps to a built-in '
                'function type and is invalid. Define a property or method on '
                'the `{instance}` instance that wraps the call to the built-in '
                'function.'.format(
                    serializer=self.parent.__class__.__name__,
                    field=self.field_name,
                    instance=instance.__class__.__name__,
                )
            )
            raise type(exc)(msg)
          except (KeyError, AttributeError) as exc:
              if self.default is not empty:
                  return self.get_default()
              if self.allow_null:
                  return None
keep keep add keep keep keep keep keep
 Raise exception when field source is a built-in (#6766) 
rest_framework/fields.py