diff --git a/fastNLP/core/dataset.py b/fastNLP/core/dataset.py
index e2a990ca..4fea967a 100644
--- a/fastNLP/core/dataset.py
+++ b/fastNLP/core/dataset.py
@@ -304,23 +304,18 @@ class DataSet(object):
         with open(csv_path, 'r') as f:
             start_idx = 0
             if headers is None:
-                headers = f.readline()
+                headers = f.readline().rstrip('\r\n')
                 headers = headers.split(sep)
                 start_idx += 1
             else:
-                assert isinstance(headers, list), "headers should be list, not {}.".format(type(headers))
+                assert isinstance(headers, (list, tuple)), "headers should be list or tuple, not {}.".format(type(headers))
             _dict = {}
             for col in headers:
                 _dict[col] = []
             for line_idx, line in enumerate(f, start_idx):
-                contents = line.split(sep)
-                if len(contents)!=len(headers):
-                    if dropna:
-                        continue
-                    else:
-                        #TODO change error type
-                        raise ValueError("Line {} has {} parts, while header has {} parts."\
-                            .format(line_idx, len(contents), len(headers)))
+                contents = line.rstrip('\r\n').split(sep)
+                assert len(contents)==len(headers), "Line {} has {} parts, while header has {}."\
+                    .format(line_idx, len(contents), len(headers))
                 for header, content in zip(headers, contents):
                     _dict[header].append(content)
-        return cls(_dict)
\ No newline at end of file
+        return cls(_dict)