fix inews bug

paddlehub/dataset/inews.py

@@ -49,15 +49,15 @@ class INews(HubDataset):
 
     def _load_train_examples(self):
         self.train_file = os.path.join(self.dataset_dir, "train.txt")
-        self.train_examples = self._read_file(self.train_file)
+        self.train_examples = self._read_file(self.train_file, is_training=True)
 
     def _load_dev_examples(self):
         self.dev_file = os.path.join(self.dataset_dir, "dev.txt")
-        self.dev_examples = self._read_file(self.dev_file)
+        self.dev_examples = self._read_file(self.dev_file, is_training=False)
 
     def _load_test_examples(self):
         self.test_file = os.path.join(self.dataset_dir, "test.txt")
-        self.test_examples = self._read_file(self.test_file)
+        self.test_examples = self._read_file(self.test_file, is_training=False)
 
     def get_train_examples(self):
         return self.train_examples
@@ -78,12 +78,12 @@ class INews(HubDataset):
         """
         return len(self.get_labels())
 
-    def _read_file(self, input_file):
+    def _read_file(self, input_file, is_training):
         """Reads a tab separated value file."""
         with io.open(input_file, "r", encoding="UTF-8") as file:
             examples = []
             for (i, line) in enumerate(file):
-                if i == 0:
+                if i == 0 and is_training:
                     continue
                 data = line.strip().split("_!_")
                 example = InputExample(