Issue #20026: Fix the sqlite module to handle correctly invalid isolation level
(wrong type).
diff --git a/Lib/sqlite3/test/regression.py b/Lib/sqlite3/test/regression.py
index 4c25f00..5b7759c 100644
--- a/Lib/sqlite3/test/regression.py
+++ b/Lib/sqlite3/test/regression.py
@@ -313,6 +313,11 @@
             datetime.datetime(2012, 4, 4, 15, 6, 0, 123456),
         ])
 
+    def CheckInvalidIsolationLevelType(self):
+        # isolation level is a string, not an integer
+        self.assertRaises(TypeError,
+                          sqlite.connect, ":memory:", isolation_level=123)
+
 
 def suite():
     regression_suite = unittest.makeSuite(RegressionTests, "Check")