[Python-checkins] r60463 - python/trunk/Doc/library/itertools.rst

Wed Jan 30 23:17:31 CET 2008

Author: raymond.hettinger
Date: Wed Jan 30 23:17:31 2008
New Revision: 60463
Modified:
 python/trunk/Doc/library/itertools.rst
Log:
Update itertool recipes
Modified: python/trunk/Doc/library/itertools.rst
==============================================================================

--- python/trunk/Doc/library/itertools.rst	(original)
+++ python/trunk/Doc/library/itertools.rst	Wed Jan 30 23:17:31 2008
@@ -401,17 +401,6 @@
 27
 64
 
- >>> reportlines = ['EuroPython', 'Roster', '', 'alex', '', 'laura',
- ... '', 'martin', '', 'walter', '', 'mark']
- >>> for name in islice(reportlines, 3, None, 2):
- ... print name.title()
- ...
- Alex
- Laura
- Martin
- Walter
- Mark
-
 # Show a dictionary sorted and grouped by value
 >>> from operator import itemgetter
 >>> d = dict(a=1, b=2, c=1, d=2, e=1, f=2, g=3)
@@ -534,5 +523,16 @@
 "grouper(3, 'abcdefg', 'x') --> ('a','b','c'), ('d','e','f'), ('g','x','x')"
 return izip(*[chain(iterable, repeat(padvalue, n-1))]*n)
 
-
+ def roundrobin(*iterables):
+ "roundrobin('abc', 'd', 'ef') --> 'a', 'd', 'e', 'b', 'f', 'c'"
+ # Recipe contributed by George Sakkis
+ pending = len(iterables)
+ nexts = cycle(iter(it).next for it in iterables)
+ while pending:
+ try:
+ for next in nexts:
+ yield next()
+ except StopIteration:
+ pending -= 1
+ nexts = cycle(islice(nexts, pending))
 
