Iterator for circulating a list

[=?ISO-8859-1?Q?BJ=F6rn_Lindqvist?=]

L = somelist

idx = 0
while True:
item = L[idx]
# Do something with item
idx = (idx + 1) % len(L)

wouldn't it be cool if there was an itertool like this:

def circulate(L, begin = 0, step = 1):
idx = begin
while True:
yield L[idx]
idx = (idx + step) % len(L)

for x in circulate(range(10)):
print 'at', x,'!'

Or maybe someone knows an even better way of expressing the above code?

 

[Hrvoje Niksic]

L = somelist

idx = 0
while True:
item = L[idx]
# Do something with item
idx = (idx + 1) % len(L)

wouldn't it be cool if there was an itertool like this:

def circulate(L, begin = 0, step = 1):
idx = begin
while True:
yield L[idx]
idx = (idx + step) % len(L)

for x in circulate(range(10)):
print 'at', x,'!'

How about itertools.cycle?