BUG: Handle concat of series with same name, GH2972

Author: Dieter Vandenbussche

pandas/tools/merge.py

@@ -947,9 +947,10 @@ def get_result(self):
             name = com._consensus_name_attr(self.objs)
             return Series(new_data, index=self.new_axes[0], name=name)
         elif self._is_series:
-            data = dict(zip(self.new_axes[1], self.objs))
-            return DataFrame(data, index=self.new_axes[0],
-                             columns=self.new_axes[1])
+            data = dict(itertools.izip(xrange(len(self.objs)), self.objs))
+            tmpdf = DataFrame(data, index=self.new_axes[0])
+            tmpdf.columns = self.new_axes[1]
+            return tmpdf
         else:
             new_data = self._get_concatenated_data()
             return self.objs[0]._from_axes(new_data, self.new_axes)

pandas/tools/tests/test_merge.py

@@ -1671,6 +1671,16 @@ def test_concat_bug_1719(self):
 
         self.assertEqual(len(left), len(right))
 
+    def test_concat_bug_2972(self):
+        ts0 = Series(np.zeros(5))
+        ts1 = Series(np.ones(5))
+        ts0.name = ts1.name = 'same name'
+        result = concat([ts0, ts1], axis=1)
+
+        expected = DataFrame({0: ts0, 1: ts1})
+        expected.columns=['same name', 'same name']
+        assert_frame_equal(result, expected)
+
 
 class TestOrderedMerge(unittest.TestCase):