From e165897c379cff56d58a8944f0089967c5723a7c Mon Sep 17 00:00:00 2001
From: littletomatodonkey <2120160898@bit.edu.cn>
Date: Thu, 6 May 2021 14:21:54 +0800
Subject: [PATCH] fix drop last for training process (#713)

---
 ppcls/data/reader.py | 10 ++++++----
 tools/eval.py        |  4 ++++
 tools/train.py       |  9 +++++++++
 3 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/ppcls/data/reader.py b/ppcls/data/reader.py
index 90bff3589..67a1c0540 100755
--- a/ppcls/data/reader.py
+++ b/ppcls/data/reader.py
@@ -197,7 +197,7 @@ class CommonDataset(Dataset):
 
     def __len__(self):
         return self.num_samples
-    
+
 
 class MultiLabelDataset(Dataset):
     """
@@ -224,9 +224,11 @@ class MultiLabelDataset(Dataset):
             labels = label_str.split(',')
             labels = [int(i) for i in labels]
 
-            return (transform(img, self.ops), np.array(labels).astype("float32"))
+            return (transform(img, self.ops),
+                    np.array(labels).astype("float32"))
         except Exception as e:
-            logger.error("data read failed: {}, exception info: {}".format(line, e))
+            logger.error("data read failed: {}, exception info: {}".format(
+                line, e))
             return self.__getitem__(random.randint(0, len(self)))
 
     def __len__(self):
@@ -291,7 +293,7 @@ class Reader:
             dataset,
             batch_size=batch_size,
             shuffle=self.shuffle and is_train,
-            drop_last=is_train)
+            drop_last=False)
         loader = DataLoader(
             dataset,
             batch_sampler=batch_sampler,
diff --git a/tools/eval.py b/tools/eval.py
index 8e0bcf16b..b214e70c6 100644
--- a/tools/eval.py
+++ b/tools/eval.py
@@ -72,6 +72,10 @@ def main(args, return_dict={}):
 
     init_model(config, net, optimizer=None)
     valid_dataloader = Reader(config, 'valid', places=place)()
+    if len(valid_dataloader) <= 0:
+        logger.error(
+            "valid dataloader is empty, please check your data config again!")
+        sys.exit(-1)
     net.eval()
     with paddle.no_grad():
         if not multilabel:
diff --git a/tools/train.py b/tools/train.py
index 48e15676c..b17175427 100644
--- a/tools/train.py
+++ b/tools/train.py
@@ -88,9 +88,18 @@ def main(args):
     init_model(config, net, optimizer)
 
     train_dataloader = Reader(config, 'train', places=place)()
+    if len(train_dataloader) <= 0:
+        logger.error(
+            "train dataloader is empty, please check your data config again!")
+        sys.exit(-1)
 
     if config.validate:
         valid_dataloader = Reader(config, 'valid', places=place)()
+        if len(valid_dataloader) <= 0:
+            logger.error(
+                "valid dataloader is empty, please check your data config again!"
+            )
+            sys.exit(-1)
 
     last_epoch_id = config.get("last_epoch", -1)
     best_top1_acc = 0.0  # best top1 acc record