Make test_str.py pass.
diff --git a/Lib/test/string_tests.py b/Lib/test/string_tests.py
index f2c9579..53a3ddb 100644
--- a/Lib/test/string_tests.py
+++ b/Lib/test/string_tests.py
@@ -1102,10 +1102,10 @@
 
     if test_support.have_unicode:
         def test_encoding_decoding(self):
-            codecs = [('rot13', 'uryyb jbeyq'),
-                      ('base64', 'aGVsbG8gd29ybGQ=\n'),
-                      ('hex', '68656c6c6f20776f726c64'),
-                      ('uu', 'begin 666 <data>\n+:&5L;&\\@=V]R;&0 \n \nend\n')]
+            codecs = [('rot13', b'uryyb jbeyq'),
+                      ('base64', b'aGVsbG8gd29ybGQ=\n'),
+                      ('hex', b'68656c6c6f20776f726c64'),
+                      ('uu', b'begin 666 <data>\n+:&5L;&\\@=V]R;&0 \n \nend\n')]
             for encoding, data in codecs:
                 self.checkequal(data, 'hello world', 'encode', encoding)
                 self.checkequal('hello world', data, 'decode', encoding)
@@ -1115,7 +1115,7 @@
             except ImportError:
                 pass
             else:
-                data = 'x\x9c\xcbH\xcd\xc9\xc9W(\xcf/\xcaI\x01\x00\x1a\x0b\x04]'
+                data = b'x\x9c\xcbH\xcd\xc9\xc9W(\xcf/\xcaI\x01\x00\x1a\x0b\x04]'
                 self.checkequal(data, 'hello world', 'encode', 'zlib')
                 self.checkequal('hello world', data, 'decode', 'zlib')