def get_slice(seq, start=0, stop=None, step=1):
    """Get a slice of a sequence with variable step. Specify start,stop,step."""
    if stop == None:
        stop = len(seq)
    item = lambda i: seq[i]
    return map(item,xrange(start,stop,step))
Get a slice of a sequence with variable step. Specify start,stop,step.