And again...

Author: h-vetinari

pandas/tests/test_algos.py

@@ -229,11 +229,13 @@ def test_complex_sorting(self):
         # gh 12666 - check no segfault
         x17 = np.array([complex(i) for i in range(17)], dtype=object)
 
-        msg = ("no ordering relation.*|unorderable types:.*"
+        msg = ("unorderable types: {0} [<>] {0}".format(r"complex\(\)")
                if _np_version_under1p14 else
                "'[<>]' not supported between instances of {0} and {0}".format(
                    "'complex'")
                )
+        if PY2:
+            msg = msg + "|no ordering relation is defined for complex numbers"
         with pytest.raises(TypeError, match=msg):
             algos.factorize(x17[::-1], sort=True)
 

pandas/tests/test_sorting.py

@@ -408,13 +408,15 @@ def test_mixed_integer_from_list(self):
     def test_unsortable(self):
         # GH 13714
         arr = np.array([1, 2, datetime.now(), 0, 3], dtype=object)
-        msg = ("can't compare.*|unorderable types:.*"
+        msg = ("unorderable types: ({0} [<>] {1}|{1} [<>] {0})".format(
+                   r"int\(\)", r"datetime\.datetime\(\)")  # noqa: E126
                if _np_version_under1p14 else
                ("'[<>]' not supported between instances of "
                 "({0} and {1}|{1} and {0})").format(
                     "'int'", r"'datetime\.datetime'")
                )
         if compat.PY2:
+            msg = msg + "|can't compare datetime.datetime to int"
             # RuntimeWarning: tp_compare didn't return -1 or -2 for exception
             with warnings.catch_warnings():
                 with pytest.raises(TypeError, match=msg):