Add example for new copydir_run_2to3().

Demo/distutils/test2to3/test/runtests.py

@@ -0,0 +1,19 @@
+# Fictitious test runner for the project
+
+import sys, os
+
+if sys.version_info > (3,):
+    # copy test suite over to "build/lib" and convert it
+    from distutils.util import copydir_run_2to3
+    testroot = os.path.dirname(__file__)
+    newroot = os.path.join(testroot, '..', 'build/lib/test')
+    copydir_run_2to3(testroot, newroot)
+    # in the following imports, pick up the converted modules
+    sys.path[0] = newroot
+
+# run the tests here...
+
+from test_foo import FooTest
+
+import unittest
+unittest.main()

Demo/distutils/test2to3/test/test_foo.py

@@ -0,0 +1,8 @@
+import sys
+import unittest
+
+class FooTest(unittest.TestCase):
+    def test_foo(self):
+        # use 2.6 syntax to demonstrate conversion
+        print 'In test_foo, using Python %s...' % (sys.version_info,)
+        self.assertTrue(False)