A very minimal start to a test of the shutil module.

Lib/test/test_shutil.py

+# Copyright (C) 2003 Python Software Foundation
+
+import unittest
+import shutil
+import tempfile
+from test import test_support
+
+class TestShutil(unittest.TestCase):
+    def test_rmtree_errors(self):
+        # filename is guaranteed not to exist
+        filename = tempfile.mktemp()
+        self.assertRaises(OSError, shutil.rmtree, filename)
+        self.assertEqual(shutil.rmtree(filename, True), None)
+
+
+
+def suite():
+    suite = unittest.TestSuite()
+    suite.addTest(unittest.makeSuite(TestShutil))
+    return suite
+
+
+def test_main():
+    test_support.run_suite(suite())
+
+
+if __name__ == '__main__':
+    unittest.main(defaultTest='suite')