Mark Lawrence wrote: > 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?
You could use a deque instead of a list and .rotate() that: >>> from collections import deque >>> d = deque(range(10)) >>> d.rotate(-4) >>> d deque([4, 5, 6, 7, 8, 9, 0, 1, 2, 3]) > > 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 > >>> -- http://mail.python.org/mailman/listinfo/python-list
