imap.py

#setattr(ThreadPoolExecutor,'imap',__import__('imap').imap)
from collections import deque
def imap(self, fn, *iterables, timeout=None, limit=None):
	if timeout is not None:
		end_time = timeout + time.time()
	if limit is None:
		limit = self._max_workers
	argv = zip(*iterables)
	fs = deque([self.submit(fn, *next(argv)) for i in range(limit)])
	def result_iterator():
		try:
			while True:
				future = fs.popleft()
				if timeout is None:
					yield future.result()
				else:
					yield future.result(end_time - time.time())
				fs.append(self.submit(fn, *next(argv)))
		finally:
			for future in fs:
				future.cancel()
	return result_iterator()