Implement itertools.groupby()
Original idea by Guido van Rossum.
Idea for skipable inner iterators by Raymond Hettinger.
Idea for argument order and identity function default by Alex Martelli.
Implementation by Hye-Shik Chang (with tweaks by Raymond Hettinger).
diff --git a/Misc/NEWS b/Misc/NEWS
index af61c4e..a28d042 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -164,6 +164,11 @@
SF bug #812202). Generators that do not define genrandbits() now
issue a warning when randrange() is called with a range that large.
+- itertools has a new function, groupby() for aggregating iterables
+ into groups sharing the same key (as determined by a key function).
+ It offers some of functionality of SQL's groupby keyword and of
+ the Unix uniq filter.
+
- itertools now has a new function, tee() which produces two independent
iterators from a single iterable.