BUG: Bug in multi-index slicing with a step in a sliced level (GH7400)

Author: jreback

doc/source/v0.14.1.txt

@@ -160,11 +160,6 @@ Bug Fixes
 
 
 
-- Bug in multi-index slicing with incomplete indexers (:issue:`7399`)
-
-
-
-- Bug in ``.ix`` getitem should always return a Series (:issue:`7150`)
 
 
 
@@ -216,3 +211,6 @@ Bug Fixes
   (:issue:`7366`).
 - Bug where ``NDFrame.replace()`` didn't correctly replace objects with
   ``Period`` values (:issue:`7379`).
+- Bug in ``.ix`` getitem should always return a Series (:issue:`7150`)
+- Bug in multi-index slicing with incomplete indexers (:issue:`7399`)
+- Bug in multi-index slicing with a step in a sliced level (:issue:`7400`)

pandas/core/index.py

@@ -3530,7 +3530,7 @@ def _get_level_indexer(self, key, level=0):
             stop  = level_index.get_loc(key.stop or len(level_index)-1)
             step = key.step
 
-            if level > 0 or self.lexsort_depth == 0:
+            if level > 0 or self.lexsort_depth == 0 or step is not None:
                 # need to have like semantics here to right
                 # searching as when we are using a slice
                 # so include the stop+1 (so we include stop)

pandas/tests/test_indexing.py

@@ -1329,14 +1329,25 @@ def test_loc_multiindex(self):
         # incomplete indexers
         s = pd.Series(np.arange(15,dtype='int64'),MultiIndex.from_product([range(5), ['a', 'b', 'c']]))
         expected = s.loc[:, 'a':'c']
+
         result = s.loc[0:4, 'a':'c']
         assert_series_equal(result, expected)
+        assert_series_equal(result, expected)
 
         result = s.loc[:4, 'a':'c']
         assert_series_equal(result, expected)
+        assert_series_equal(result, expected)
 
         result = s.loc[0:, 'a':'c']
         assert_series_equal(result, expected)
+        assert_series_equal(result, expected)
+
+        # GH 7400
+        # multiindexer gettitem with list of indexers skips wrong element
+        s = pd.Series(np.arange(15,dtype='int64'),MultiIndex.from_product([range(5), ['a', 'b', 'c']]))
+        expected = s.iloc[[6,7,8,12,13,14]]
+        result = s.loc[2:4:2, 'a':'c']
+        assert_series_equal(result, expected)
 
     def test_series_getitem_multiindex(self):