changes based on review

Author: charlesdong1991

pandas/tests/frame/test_to_csv.py

@@ -120,7 +120,6 @@ def test_to_csv_from_csv3(self):
 
             df1.to_csv(path)
             df2.to_csv(path, mode='a', header=False)
-
             xp = pd.concat([df1, df2])
             rs = pd.read_csv(path, index_col=0)
             rs.columns = lmap(int, rs.columns)

pandas/tests/io/formats/test_to_csv.py

@@ -564,36 +564,35 @@ def test_to_csv_compression(self, compression_only,
 
     @pytest.mark.parametrize("header, index_label, expected_rows", [
         (False, True, ['index.name,,', '0,0,0', '1,0,0']),
-        (True, True, ['index.name,A,B', '0,0,0', '1,0,0']),
+        (True, True, ['index.name,0,1', '0,0,0', '1,0,0']),
         (False, False, ['0,0,0', '1,0,0']),
-        (True, False, [',A,B', '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,A,B', '0,0,0', '1,0,0'])
+        (True, None, ['index.name,0,1', '0,0,0', '1,0,0'])
     ])
     def test_to_csv_header_single_index(self, header, index_label,
                                         expected_rows):
         # issue 24546
         df = pd.DataFrame(np.zeros((2, 2), dtype=int))
         df.index.name = 'index.name'
-        df.columns = ['A', 'B']
+        df.columns.name = 'columns.name'
 
         result = df.to_csv(header=header, index_label=index_label)
         expected = tm.convert_rows_list_to_csv_str(expected_rows)
         assert result == expected
 
     @pytest.mark.parametrize("header, index_label, expected_rows", [
         (False, True, ['index.name.0,index.name.1,,', 'a,b,0,0', 'a,c,0,0']),
-        (True, True, ['index.name.0,index.name.1,A,B', 'a,b,0,0', 'a,c,0,0']),
+        (True, True, ['index.name.0,index.name.1,0,1', 'a,b,0,0', 'a,c,0,0']),
         (False, False, ['a,b,0,0', 'a,c,0,0']),
-        (True, False, [',,A,B', '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,A,B', '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'])
     ])
     def test_to_csv_header_multi_index(self, header, index_label,
                                        expected_rows):
         # issue 24546
         df = pd.DataFrame(np.zeros((2, 2), dtype=int))
-        df.columns = ['A', 'B']
         df.index = pd.MultiIndex.from_product([['a'], ['b', 'c']], names=[
             'index.name.0', 'index.name.1'])