check if eval dataset is dict (#24877)

* check if eval dataset is dict

* formatting

examples/pytorch/summarization/run_summarization.py

@@ -692,7 +692,13 @@ def main():
     results = {}
     if training_args.do_eval:
         logger.info("*** Evaluate ***")
-        metrics = trainer.evaluate(metric_key_prefix="eval")
+        if isinstance(eval_dataset, dict):
+            metrics = {}
+            for eval_ds_name, eval_ds in eval_dataset.items():
+                dataset_metrics = trainer.evaluate(eval_dataset=eval_ds, metric_key_prefix=f"eval_{eval_ds_name}")
+                metrics.update(dataset_metrics)
+        else:
+            metrics = trainer.evaluate(metric_key_prefix="eval")
         max_eval_samples = data_args.max_eval_samples if data_args.max_eval_samples is not None else len(eval_dataset)
         metrics["eval_samples"] = min(max_eval_samples, len(eval_dataset))