Merge pull request #5512 from jreback/indexing_bug

BUG: Fixed various setitem with iterable that does not have a matching length to the indexer (GH5508)

Author: jreback

doc/source/release.rst

@@ -805,6 +805,8 @@ Bug Fixes
   - ``pd.to_timedelta`` of a scalar returns a scalar (:issue:`5410`)
   - ``pd.to_timedelta`` accepts ``NaN`` and ``NaT``, returning ``NaT`` instead of raising (:issue:`5437`)
   - performance improvements in ``isnull`` on larger size pandas objects
+  - Fixed various setitem with 1d ndarray that does not have a matching
+    length to the indexer (:issue:`5508`)
 
 pandas 0.12.0
 -------------

pandas/core/indexing.py

@@ -365,6 +365,10 @@ def can_do_equal_len():
                 # per label values
                 else:
 
+                    if len(labels) != len(value):
+                        raise ValueError('Must have equal len keys and value when'
+                                         ' setting with an iterable')
+
                     for item, v in zip(labels, value):
                         setter(item, v)
             else:

pandas/tests/test_indexing.py

@@ -650,6 +650,35 @@ def test_iloc_getitem_frame(self):
         # trying to use a label
         self.assertRaises(ValueError, df.iloc.__getitem__, tuple(['j','D']))
 
+    def test_setitem_ndarray_1d(self):
+        # GH5508
+
+        # len of indexer vs length of the 1d ndarray
+        df = DataFrame(index=Index(lrange(1,11)))
+        df['foo'] = np.zeros(10, dtype=np.float64)
+        df['bar'] = np.zeros(10, dtype=np.complex)
+
+        # invalid
+        def f():
+            df.ix[2:5, 'bar'] = np.array([2.33j, 1.23+0.1j, 2.2])
+        self.assertRaises(ValueError, f)
+
+        # valid
+        df.ix[2:5, 'bar'] = np.array([2.33j, 1.23+0.1j, 2.2, 1.0])
+
+        result = df.ix[2:5, 'bar']
+        expected = Series([2.33j, 1.23+0.1j, 2.2, 1.0],index=[2,3,4,5])
+        assert_series_equal(result,expected)
+
+        # dtype getting changed?
+        df = DataFrame(index=Index(lrange(1,11)))
+        df['foo'] = np.zeros(10, dtype=np.float64)
+        df['bar'] = np.zeros(10, dtype=np.complex)
+
+        def f():
+            df[2:5] = np.arange(1,4)*1j
+        self.assertRaises(ValueError, f)
+
     def test_iloc_setitem_series(self):
         """ originally from test_series.py """
         df = DataFrame(np.random.randn(10, 4), index=list('abcdefghij'), columns=list('ABCD'))