Merge pull request #11653 from jreback/range

BUG: indexing with a range , #11652

Author: jreback

doc/source/whatsnew/v0.17.1.txt

@@ -169,7 +169,7 @@ Bug Fixes
 
 
 
-
+- Bug in indexing with a ``range``, (:issue:`11652`)
 
 
 - Bug in ``to_sql`` using unicode column names giving UnicodeEncodeError with (:issue:`11431`).

pandas/core/index.py

@@ -1755,7 +1755,8 @@ def get_loc(self, key, method=None, tolerance=None):
             if tolerance is not None:
                 raise ValueError('tolerance argument only valid if using pad, '
                                  'backfill or nearest lookups')
-            return self._engine.get_loc(_values_from_object(key))
+            key = _values_from_object(key)
+            return self._engine.get_loc(key)
 
         indexer = self.get_indexer([key], method=method,
                                    tolerance=tolerance)

pandas/core/indexing.py

@@ -104,6 +104,8 @@ def _get_setitem_indexer(self, key):
 
         if isinstance(key, tuple) and not self.ndim < len(key):
             return self._convert_tuple(key, is_setter=True)
+        if isinstance(key, range):
+            return self._convert_range(key, is_setter=True)
 
         try:
             return self._convert_to_indexer(key, is_setter=True)
@@ -156,6 +158,10 @@ def _convert_tuple(self, key, is_setter=False):
                 keyidx.append(idx)
         return tuple(keyidx)
 
+    def _convert_range(self, key, is_setter=False):
+        """ convert a range argument """
+        return list(key)
+
     def _convert_scalar_indexer(self, key, axis):
         # if we are accessing via lowered dim, use the last dim
         ax = self.obj._get_axis(min(axis, self.ndim - 1))

pandas/tests/test_indexing.py

@@ -4726,6 +4726,17 @@ def test_indexing_dtypes_on_empty(self):
         assert_series_equal(df2.loc[:,'a'], df2.iloc[:,0])
         assert_series_equal(df2.loc[:,'a'], df2.ix[:,0])
 
+    def test_range_in_series_indexing(self):
+        # range can cause an indexing error
+        # GH 11652
+        for x in [5, 999999, 1000000]:
+            s = pd.Series(index=range(x))
+            s.loc[range(1)] = 42
+            assert_series_equal(s.loc[range(1)],Series(42.0,index=[0]))
+
+            s.loc[range(2)] = 43
+            assert_series_equal(s.loc[range(2)],Series(43.0,index=[0,1]))
+
     @slow
     def test_large_dataframe_indexing(self):
         #GH10692