REALLY need help with iterating a list.

[Radamand]

    This has been driving me buggy for 2 days, i need to be able to
iterate a list of items until none are left, without regard to which
items are removed. I'll put the relevant portions of code below,
please forgive my attrocious naming conventions.
    Basically i'm trying to spin up some subprocesses that will ping a
group of servers and then wait until all of them have completed (good
or bad), store the ping result and the return code, and move on.
    The problem comes in the second block, when i try to iterate the
list of servers and remove the ones that are finished, for some reason
Python appears to re-index the list when I remove an item and the next
step through the loop it cant find the item its expecting because the
indexes have changed.
    Any assistance would be appreciated...

=============================================================================
for server in serverlist:
    ping[server] = subprocess.Popen("ping -c 1 " + str(server) + " 5",
shell=True, stdout=subprocess.PIPE)

while len(serverlist) > 0:
    for server in serverlist:
        if ping[server].returncode==None:
            ping[server].poll()
        else:
            pingresult[server] = ping[server].stdout.read()
            pingreturncode[server] = ping[server].returncode
            serverlist.remove(server)