fix logger info for empty log

tools/program.py

@@ -237,8 +237,9 @@ def train(config,
                     vdl_writer.add_scalar('TRAIN/{}'.format(k), v, global_step)
                 vdl_writer.add_scalar('TRAIN/lr', lr, global_step)
 
-            if dist.get_rank(
-            ) == 0 and global_step > 0 and global_step % print_batch_step == 0:
+            if dist.get_rank() == 0 and (
+                (global_step > 0 and global_step % print_batch_step == 0) or
+                (idx >= len(train_dataloader) - 1)):
                 logs = train_stats.log()
                 strs = 'epoch: [{}/{}], iter: {}, {}, reader_cost: {:.5f} s, batch_cost: {:.5f} s, samples: {}, ips: {:.5f}'.format(
                     epoch, epoch_num, global_step, logs, train_reader_cost /

tools/train.py

@@ -52,7 +52,10 @@ def main(config, device, logger, vdl_writer):
     train_dataloader = build_dataloader(config, 'Train', device, logger)
     if len(train_dataloader) == 0:
         logger.error(
-            'No Images in train dataset, please check annotation file and path in the configuration file'
+            "No Images in train dataset, please ensure\n" +
+            "\t1. The images num in the train label_file_list should be larger than or equal with batch size.\n"
+            +
+            "\t2. The annotation file and path in the configuration file are provided normally."
         )
         return