#!/usr/bin/python2

#!/usr/bin/env python2

    line = 0
    while line != '':
        line = fil.readline()
        yield line

    the_line = 0
    while the_line != '':
        the_line = fil.readline()
        yield the_line

    buffer = []

    the_buffer = []
    for the_line in gen:
        # print("pushing: ", the_line, end='')
        heapq.heappush(the_buffer, the_line)
        if len(the_buffer) == len_:
            yield heapq.heappop(the_buffer)
        # print("buffer_after: ", repr(the_buffer))
    while the_buffer != []:
        yield heapq.heappop(the_buffer)
        # print("buffer_after: ", repr(the_buffer))

    for line in gen:
        heapq.heappush(buffer, line)
        if len(buffer) == len_:
            yield heapq.heappop(buffer)

        print('>', line, end='')

        print(line, end='')