Improve DictMixin.
Replaced docstring with comments. Prevents subclass contamination.
Added the missing __cmp__() method and a test for __cmp__().
Used try/except style in preference to has_key() followed by a look-up.
Used iteritem() where possible to save creating a long key list and
to save redundant lookups.
Expanded .update() to look for the most helpful methods first and gradually
work down to a mininum expected interface.
Expanded documentation to be more clear on how to use the class.
diff --git a/Lib/test/test_userdict.py b/Lib/test/test_userdict.py
index 6f3b853..a59419d 100644
--- a/Lib/test/test_userdict.py
+++ b/Lib/test/test_userdict.py
@@ -210,9 +210,8 @@
s.update({10: 'ten', 20:'twenty'}) # update
verify(s[10]=='ten' and s[20]=='twenty')
-
-
-
-
-
-
+verify(s == {10: 'ten', 20:'twenty'}) # cmp
+t = SeqDict()
+t[20] = 'twenty'
+t[10] = 'ten'
+verify(s == t)