"The specificed validation_field {} is not valid."
"Available ones are: {}".format(
self._validation_field,
[of[NAME] for of in output_features] + ["combined"]
)
)
After Change
"The specificed validation_field {} is not valid."
"Available ones are: {}".format(
self._validation_field,
list(output_features.keys()) + ["combined"]
)
)