Merge pull request pandas-dev#5429 from jmcnamara/bug_excel_cols_option

BUG: Excel writer doesn't handle "cols" option correctly
bingo · Nov 6, 2013 · 80d8a7a · 80d8a7a
2 parents 3c57949 + 96134ba
commit 80d8a7a
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Showing 2 changed files with 25 additions and 3 deletions.
diff --git a/pandas/core/format.py b/pandas/core/format.py
@@ -1393,8 +1393,12 @@ def _format_regular_rows(self):
             for idx, idxval in enumerate(index_values):
                 yield ExcelCell(self.rowcounter + idx, 0, idxval, header_style)
 
+        # Get a frame that will account for any duplicates in the column names.
+        col_mapped_frame = self.df.loc[:, self.columns]
+
+        # Write the body of the frame data series by series.
         for colidx in range(len(self.columns)):
-            series = self.df.iloc[:, colidx]
+            series = col_mapped_frame.iloc[:, colidx]
             for i, val in enumerate(series):
                 yield ExcelCell(self.rowcounter + i, colidx + coloffset, val)
 
@@ -1461,8 +1465,12 @@ def _format_hierarchical_rows(self):
                                         header_style)
                     gcolidx += 1
 
+        # Get a frame that will account for any duplicates in the column names.
+        col_mapped_frame = self.df.loc[:, self.columns]
+
+        # Write the body of the frame data series by series.
         for colidx in range(len(self.columns)):
-            series = self.df.iloc[:, colidx]
+            series = col_mapped_frame.iloc[:, colidx]
             for i, val in enumerate(series):
                 yield ExcelCell(self.rowcounter + i, gcolidx + colidx, val)
 

diff --git a/pandas/io/tests/test_excel.py b/pandas/io/tests/test_excel.py
@@ -922,11 +922,25 @@ def test_duplicated_columns(self):
             write_frame.columns = colnames
             write_frame.to_excel(path, 'test1')
 
-            read_frame = read_excel(path, 'test1').astype(np.int64)
+            read_frame = read_excel(path, 'test1')
             read_frame.columns = colnames
 
             tm.assert_frame_equal(write_frame, read_frame)
 
+    def test_swapped_columns(self):
+        # Test for issue #5427.
+        _skip_if_no_xlrd()
+
+        with ensure_clean(self.ext) as path:
+            write_frame = DataFrame({'A': [1, 1, 1],
+                                     'B': [2, 2, 2]})
+            write_frame.to_excel(path, 'test1', cols=['B', 'A'])
+
+            read_frame = read_excel(path, 'test1', header=0)
+
+            tm.assert_series_equal(write_frame['A'], read_frame['A'])
+            tm.assert_series_equal(write_frame['B'], read_frame['B'])
+
 
 class OpenpyxlTests(ExcelWriterBase, unittest.TestCase):
     ext = '.xlsx'