diff -r 6b3523f81f42 -r 26744ad37953 cubicweb/test/unittest_rset.py
--- a/cubicweb/test/unittest_rset.py	Fri Apr 05 17:21:14 2019 +0200
+++ b/cubicweb/test/unittest_rset.py	Fri Apr 05 17:58:19 2019 +0200
@@ -18,9 +18,8 @@
 # with CubicWeb.  If not, see <http://www.gnu.org/licenses/>.
 """unit tests for module cubicweb.rset"""
 
-from six import string_types
-from six.moves import cPickle as pickle
-from six.moves.urllib.parse import urlsplit
+import pickle
+from urllib.parse import urlsplit
 
 from rql import parse
 
@@ -655,17 +654,17 @@
     def test_str(self):
         with self.admin_access.web_request() as req:
             rset = req.execute('(Any X,N WHERE X is CWGroup, X name N)')
-            self.assertIsInstance(str(rset), string_types)
+            self.assertIsInstance(str(rset), str)
             self.assertEqual(len(str(rset).splitlines()), 1)
 
     def test_repr(self):
         with self.admin_access.web_request() as req:
             rset = req.execute('(Any X,N WHERE X is CWGroup, X name N)')
-            self.assertIsInstance(repr(rset), string_types)
+            self.assertIsInstance(repr(rset), str)
             self.assertTrue(len(repr(rset).splitlines()) > 1)
 
             rset = req.execute('(Any X WHERE X is CWGroup, X name "managers")')
-            self.assertIsInstance(str(rset), string_types)
+            self.assertIsInstance(str(rset), str)
             self.assertEqual(len(str(rset).splitlines()), 1)
 
     def test_slice(self):