BUG: Bug in list-like indexing with a mixed-integer Index, pandas-dev#11320

Author: jreback

doc/source/whatsnew/v0.17.1.txt

@@ -65,7 +65,7 @@ Bug Fixes
 - Bug in tz-conversions with an ambiguous time and ``.dt`` accessors (:issues:`11295`)
 
 
-
+- Bug in list-like indexing with a mixed-integer Index (:issue:`11320`)
 
 
 

pandas/core/index.py

@@ -982,10 +982,6 @@ def _convert_list_indexer(self, keyarr, kind=None):
         if kind in [None, 'iloc', 'ix'] and is_integer_dtype(keyarr) \
            and not self.is_floating() and not isinstance(keyarr, ABCPeriodIndex):
 
-            if self.inferred_type != 'integer':
-                keyarr = np.where(keyarr < 0,
-                                  len(self) + keyarr, keyarr)
-
             if self.inferred_type == 'mixed-integer':
                 indexer = self.get_indexer(keyarr)
                 if (indexer >= 0).all():
@@ -998,6 +994,8 @@ def _convert_list_indexer(self, keyarr, kind=None):
                 return maybe_convert_indices(indexer, len(self))
 
             elif not self.inferred_type == 'integer':
+                keyarr = np.where(keyarr < 0,
+                                  len(self) + keyarr, keyarr)
                 return keyarr
 
         return None

pandas/tests/test_frame.py

@@ -488,6 +488,18 @@ def test_getitem_ix_mixed_integer(self):
         expected = df.ix[Index([1, 10], dtype=object)]
         assert_frame_equal(result, expected)
 
+        # 11320
+        df = pd.DataFrame({ "rna": (1.5,2.2,3.2,4.5),
+                            -1000: [11,21,36,40],
+                            0: [10,22,43,34],
+                            1000:[0, 10, 20, 30] },columns=['rna',-1000,0,1000])
+        result = df[[1000]]
+        expected = df.iloc[:,[3]]
+        assert_frame_equal(result, expected)
+        result = df[[-1000]]
+        expected = df.iloc[:,[1]]
+        assert_frame_equal(result, expected)
+
     def test_getitem_setitem_ix_negative_integers(self):
         result = self.frame.ix[:, -1]
         assert_series_equal(result, self.frame['D'])