Fix for issue pandas-dev#11317

This includes updates to 3 Excel files, plus a test in test_excel.py,
plus the fix in parsers.py

Author: Dr-Irv

pandas/io/parsers.py

@@ -867,7 +867,7 @@ def _extract_multi_indexer_columns(self, header, index_names, col_names,
         field_count = len(header[0])
 
         def extract(r):
-            return tuple([r[i] for i in range(field_count) if i not in sic])
+            return tuple([str(r[i]) for i in range(field_count) if i not in sic])
 
         columns = lzip(*[extract(r) for r in header])
         names = ic + columns

pandas/io/tests/data/testmultiindex.xls

@@ -557,6 +557,12 @@ def test_read_excel_multiindex(self):
         actual = read_excel(mi_file, 'mi_column_name', header=[0,1], index_col=0)
         tm.assert_frame_equal(actual, expected)
 
+        # Issue #11317
+        expected.columns = mi.set_levels(['1','2'],level=1).set_names(['c1', 'c2'])
+        actual = read_excel(mi_file, 'name_with_int', index_col=0, header=[0,1])
+        tm.assert_frame_equal(actual, expected)
+        
+        expected.columns = mi.set_names(['c1', 'c2'])
         expected.index = mi.set_names(['ilvl1', 'ilvl2'])
         actual = read_excel(mi_file, 'both_name', index_col=[0,1], header=[0,1])
         tm.assert_frame_equal(actual, expected)