从迭代器(python)中排除第一个元素

next(it)

• StopIteration
• except StopIteration: raise SomethingElse()
• next(it, None)

itertools

def pairwise(iterable):
    "s -> (s0,s1), (s1,s2), (s2, s3), ..."
    a, b = tee(iterable)
    next(b, None)
    return zip(a, b)

b iterable next(b, None)

def skip_first(iterable):
    it = iter(iterable)
    next(it, None)
    return it

def skip_first(iterable):
    it = iter(iterable)
    next(it, None)
    yield from it

itertools.islice

it = skip_first(it)
it = itertools.islice(it, 1, None)

consume

def consume(iterator, n=None):
    "Advance the iterator n-steps ahead. If n is None, consume entirely."
    # Use functions that consume iterators at C speed.
    if n is None:
        # feed the entire iterator into a zero-length deque
        collections.deque(iterator, maxlen=0)
    else:
        # advance to the empty slice starting at position n
        next(islice(iterator, n, n), None)

None n islice next iterator

itertools.islice

itertools.islice(generator,1,None)

免责声明:见上文@abarnet和@solaxun的回答。

只是觉得应该提到以下几点

如果你有,例如 original = iter((1,2,3,4,5))

然后

first, remaining = next(original), original

哪里 remaining 是没有第一个元素的迭代器。