drop.py

import collections

def drop(iterable, n):
    iterator = iter(iterable)
    buffer = collections.deque()
    for _ in range(n):
        try:
            val = next(iterator)
        except StopIteration:
            return
        buffer.append(val)
    while True:
        try:
            val = next(iterator)
        except StopIteration:
            return
        buffer.append(val)
        yield buffer.popleft()
        
-------------------------------- Or more succinctly, with itertools ---------------------------------------


import collections
import itertools

def drop(iterable, n):
    iterator = iter(iterable)
    buffer = collections.deque()
    buffer.extend(itertools.islice(iterator, n))
    while True:
        try:
            val = next(iterator)
        except StopIteration:
            return
        buffer.append(val)
        yield buffer.popleft()