A few extra itertools-esque snippets

extraitertools.py

import collections
import itertools

def last(iterable, deque=collections.deque):
    return deque(iterable, maxlen = 1)[0]

def iterlen(iterable):
    return sum(1 for _ in iterable)

def droptake(iterable, takecondition, dropcondition = None,
                takewhile = itertools.takewhile, dropwhile = itertools.dropwhile):
    return takewhile(dropwhile(iterable,
        dropcondition or (lambda item: not takecondition(item))), takecondition)

def prepend(iterable, *items):
    for item in itertools.chain(items, iterable):
        yield item

def append(iterable, *items):
    for item in itertools.chain(iterable, items):
        yield item

def skip(iterable, at_start=0, at_end=0):
    it = iter(iterable)
    for x in itertools.islice(it, at_start):
        pass
    if not at_end:
        return it
    queue = collections.deque(itertools.islice(it, at_end), at_end + 1)
    return (queue.append(x) or queue[0] for x in it)

def reduceself(func, obj, times):
    return reduce((lambda (ob, _): func(ob)), range(times), obj)