Groups > comp.lang.python > #19996

Cycle around a sequence

From	Mark Lawrence <breamoreboy@yahoo.co.uk>
Subject	Cycle around a sequence
Date	2012-02-08 01:10 +0000
Newsgroups	comp.lang.python
Message-ID	<mailman.5525.1328663401.27778.python-list@python.org> (permalink)

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I'm looking at a way of cycling around a sequence i.e. starting at some 
given location in the middle of a sequence and running to the end before 
coming back to the beginning and running to the start place.  About the 
best I could come up with is the following, any better ideas for some 
definition of better?

PythonWin 2.7.2 (default, Jun 12 2011, 15:08:59) [MSC v.1500 32 bit 
(Intel)] on win32.
Portions Copyright 1994-2008 Mark Hammond - see 'Help/About PythonWin' 
for further copyright information.
 >>> from itertools import chain
 >>> a=range(10)
 >>> g = chain((a[i] for i in xrange(4, 10, 1)), (a[i] for i in xrange(4)))
 >>> for x in g: print x,
...
4 5 6 7 8 9 0 1 2 3
 >>>
-- 
Cheers.

Mark Lawrence.

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Thread

Cycle around a sequence Mark Lawrence <breamoreboy@yahoo.co.uk> - 2012-02-08 01:10 +0000
  Re: Cycle around a sequence Christoph Hansen <ch@radamanthys.de> - 2012-02-08 03:01 +0100
  Re: Cycle around a sequence Neil Cerutti <neilc@norwich.edu> - 2012-02-08 14:25 +0000
    Re: Cycle around a sequence Terry Reedy <tjreedy@udel.edu> - 2012-02-08 15:15 -0500
    Re: Cycle around a sequence Mark Lawrence <breamoreboy@yahoo.co.uk> - 2012-02-08 22:47 +0000
    Re: Cycle around a sequence Serhiy Storchaka <storchaka@gmail.com> - 2012-02-09 12:10 +0200
  Re: Cycle around a sequence Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-02-09 03:55 +0000
    Re: Cycle around a sequence Chris Angelico <rosuav@gmail.com> - 2012-02-09 15:16 +1100
    Re: Cycle around a sequence Peter Otten <__peter__@web.de> - 2012-02-09 09:33 +0100
    Re: Cycle around a sequence Chris Angelico <rosuav@gmail.com> - 2012-02-09 21:34 +1100

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