Fix test_hashlib regression caused by my fixing hexdigest() to return

a text string instead of bytes.  (This being hex digits it *should*
be a text string -- that it wasn't before was a misunderstanding on
my part of the C code.)

Lib/test/test_hashlib.py

@@ -13,11 +13,10 @@ from test import test_support
 
 def hexstr(s):
     assert isinstance(s, bytes), repr(s)
-    h = b"0123456789abcdef"
-    r = b''
+    h = "0123456789abcdef"
+    r = ''
     for i in s:
-        r.append(h[(i >> 4) & 0xF])
-        r.append(h[i & 0xF])
+        r += h[(i >> 4) & 0xF] + h[i & 0xF]
     return r
 
 
@@ -60,22 +59,22 @@ class HashLibTestCase(unittest.TestCase):
     def check(self, name, data, digest):
         # test the direct constructors
         computed = getattr(hashlib, name)(data).hexdigest()
-        self.assert_(computed == digest)
+        self.assertEqual(computed, digest)
         # test the general new() interface
         computed = hashlib.new(name, data).hexdigest()
-        self.assert_(computed == digest)
+        self.assertEqual(computed, digest)
 
 
     def test_case_md5_0(self):
-        self.check('md5', b'', b'd41d8cd98f00b204e9800998ecf8427e')
+        self.check('md5', b'', 'd41d8cd98f00b204e9800998ecf8427e')
 
     def test_case_md5_1(self):
-        self.check('md5', b'abc', b'900150983cd24fb0d6963f7d28e17f72')
+        self.check('md5', b'abc', '900150983cd24fb0d6963f7d28e17f72')
 
     def test_case_md5_2(self):
         self.check('md5',
                    b'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789',
-                   b'd174ab98d277d9f5a5611c2c9f419d9f')
+                   'd174ab98d277d9f5a5611c2c9f419d9f')
 
 
     # use the three examples from Federal Information Processing Standards
@@ -84,20 +83,20 @@ class HashLibTestCase(unittest.TestCase):
 
     def test_case_sha1_0(self):
         self.check('sha1', b"",
-                   b"da39a3ee5e6b4b0d3255bfef95601890afd80709")
+                   "da39a3ee5e6b4b0d3255bfef95601890afd80709")
 
     def test_case_sha1_1(self):
         self.check('sha1', b"abc",
-                   b"a9993e364706816aba3e25717850c26c9cd0d89d")
+                   "a9993e364706816aba3e25717850c26c9cd0d89d")
 
     def test_case_sha1_2(self):
         self.check('sha1',
                    b"abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq",
-                   b"84983e441c3bd26ebaae4aa1f95129e5e54670f1")
+                   "84983e441c3bd26ebaae4aa1f95129e5e54670f1")
 
     def test_case_sha1_3(self):
         self.check('sha1', b"a" * 1000000,
-                   b"34aa973cd4c4daa4f61eeb2bdbad27316534016f")
+                   "34aa973cd4c4daa4f61eeb2bdbad27316534016f")
 
 
     # use the examples from Federal Information Processing Standards