BUG: handle incomparable values when creating Factor, caused bug in py3

Author: wesm

pandas/core/index.py

@@ -1002,11 +1002,14 @@ def unique_with_labels(values):
     labels, _ = rizer.factorize(values, sort=False)
     uniques = Index(rizer.uniques)
 
-    sorter = uniques.argsort()
-    reverse_indexer = np.empty(len(sorter), dtype='i4')
-    reverse_indexer.put(sorter, np.arange(len(sorter)))
-    labels = reverse_indexer.take(labels)
-    uniques = uniques.take(sorter)
+    try:
+        sorter = uniques.argsort()
+        reverse_indexer = np.empty(len(sorter), dtype='i4')
+        reverse_indexer.put(sorter, np.arange(len(sorter)))
+        labels = reverse_indexer.take(labels)
+        uniques = uniques.take(sorter)
+    except TypeError:
+        pass
 
     return uniques, labels
 

pandas/tests/test_index.py

@@ -1349,6 +1349,12 @@ def test_getitem(self):
         subf = self.factor[self.factor.asarray() == 'c']
         tm.assert_almost_equal(subf.labels, [2, 2, 2])
 
+    def test_constructor_unsortable(self):
+        arr = np.array([1, 2, 3, datetime.now()], dtype='O')
+
+        # it works!
+        factor = Factor(arr)
+
     def test_factor_agg(self):
         import pandas.core.frame as frame