TST: Adds test for uint64 handling in factorize

Author: gfyoung

pandas/tests/test_algos.py

@@ -287,6 +287,23 @@ def test_complex_sorting(self):
 
         self.assertRaises(TypeError, algos.factorize, x17[::-1], sort=True)
 
+    def test_uint64_factorize(self):
+        data = np.array([2**63, 1, 2**63], dtype=np.uint64)
+        exp_labels = np.array([0, 1, 0], dtype=np.intp)
+        exp_uniques = np.array([2**63, 1], dtype=np.uint64)
+
+        labels, uniques = algos.factorize(data)
+        tm.assert_numpy_array_equal(labels, exp_labels)
+        tm.assert_numpy_array_equal(uniques, exp_uniques)
+
+        data = np.array([2**63, -1, 2**63], dtype=object)
+        exp_labels = np.array([0, 1, 0], dtype=np.intp)
+        exp_uniques = np.array([2**63, -1], dtype=object)
+
+        labels, uniques = algos.factorize(data)
+        tm.assert_numpy_array_equal(labels, exp_labels)
+        tm.assert_numpy_array_equal(uniques, exp_uniques)
+
 
 class TestUnique(tm.TestCase):
     _multiprocess_can_split_ = True