!6699 add dataset size check

Merge pull request !6699 from wukesong/add-dataset-check

model_zoo/official/cv/alexnet/eval.py

@@ -77,5 +77,8 @@ if __name__ == "__main__":
     else:
         raise ValueError("Unsupport dataset.")
 
+    if ds_eval.get_dataset_size() == 0:
+        raise ValueError("Please check dataset size > 0 and batch_size <= dataset size")
+
     result = model.eval(ds_eval, dataset_sink_mode=args.dataset_sink_mode)
     print("result : {}".format(result))

model_zoo/official/cv/alexnet/train.py

@@ -91,6 +91,9 @@ if __name__ == "__main__":
     else:
         raise ValueError("Unsupport dataset.")
 
+    if ds_train.get_dataset_size() == 0:
+        raise ValueError("Please check dataset size > 0 and batch_size <= dataset size")
+
     network = AlexNet(cfg.num_classes)
 
     loss_scale_manager = None

model_zoo/official/cv/lenet/eval.py

@@ -57,5 +57,8 @@ if __name__ == "__main__":
     ds_eval = create_dataset(os.path.join(args.data_path, "test"),
                              cfg.batch_size,
                              1)
+    if ds_eval.get_dataset_size() == 0:
+        raise ValueError("Please check dataset size > 0 and batch_size <= dataset size")
+
     acc = model.eval(ds_eval, dataset_sink_mode=args.dataset_sink_mode)
     print("============== {} ==============".format(acc))

model_zoo/official/cv/lenet/train.py

@@ -50,6 +50,8 @@ if __name__ == "__main__":
     context.set_context(mode=context.GRAPH_MODE, device_target=args.device_target)
     ds_train = create_dataset(os.path.join(args.data_path, "train"),
                               cfg.batch_size)
+    if ds_train.get_dataset_size() == 0:
+        raise ValueError("Please check dataset size > 0 and batch_size <= dataset size")
 
     network = LeNet5(cfg.num_classes)
     net_loss = nn.SoftmaxCrossEntropyWithLogits(sparse=True, reduction="mean")