changed based on wil review

Author: charlesdong1991

pandas/io/formats/csvs.py

@@ -199,19 +199,24 @@ def save(self):
                     _fh.close()
 
     def _index_label_encoder(self):
-        """Encode index label if it is not False.
-
-        Returns:
-            index_label: new index_label given index types
-            encode_labels: list of index labels
+        """
+        Encode index label if it is not False.
+
+        Returns
+        -------
+        index_label: list
+            New index_label given index types
+        encode_labels: list
+            List of index labels
         """
         index_label = self.index_label
         obj = self.obj
-        if index_label:
+
+        if index_label is True:
             # append index label based on index type
             if isinstance(obj.index, ABCMultiIndex):
                 index_label = []
-                for i, name in enumerate(obj.index.names):
+                for name in obj.index.names:
                     # add empty string is name is None
                     if name is None:
                         name = ''
@@ -225,7 +230,6 @@ def _index_label_encoder(self):
                     index_label = [index_label]
         elif not isinstance(index_label,
                             (list, tuple, np.ndarray, ABCIndexClass)):
-            # given a string for a DF with Index
             index_label = [index_label]
 
         encoded_labels = list(index_label)

pandas/tests/io/formats/test_to_csv.py

@@ -568,7 +568,9 @@ def test_to_csv_compression(self, compression_only,
         (False, False, ['0,0,0', '1,0,0']),
         (True, False, [',0,1', '0,0,0', '1,0,0']),
         (False, None, ['0,0,0', '1,0,0']),
-        (True, None, ['index.name,0,1', '0,0,0', '1,0,0'])
+        (True, None, ['index.name,0,1', '0,0,0', '1,0,0']),
+        (True, "new_index", ['new_index,0,1', '0,0,0', '1,0,0']),
+        (True, ["new_index"], ['new_index,0,1', '0,0,0', '1,0,0'])
     ])
     def test_to_csv_header_single_index(self, header, index_label,
                                         expected_rows):
@@ -587,7 +589,11 @@ def test_to_csv_header_single_index(self, header, index_label,
         (False, False, ['a,b,0,0', 'a,c,0,0']),
         (True, False, [',,0,1', 'a,b,0,0', 'a,c,0,0']),
         (False, None, ['a,b,0,0', 'a,c,0,0']),
-        (True, None, ['index.name.0,index.name.1,0,1', 'a,b,0,0', 'a,c,0,0'])
+        (True, None, ['index.name.0,index.name.1,0,1', 'a,b,0,0', 'a,c,0,0']),
+        (True, ("index1", "index2"),
+         ['index1,index2,0,1', 'a,b,0,0', 'a,c,0,0']),
+        (True, ["index1", "index2"],
+         ['index1,index2,0,1', 'a,b,0,0', 'a,c,0,0'])
     ])
     def test_to_csv_header_multi_index(self, header, index_label,
                                        expected_rows):