更深入 - 从内部收益率中收益

Question

是否有一个单线轮来接收发电机并产生该发电机中的所有元件？例如:

def Yearly(year):
  yield YEARLY_HEADER
  for month in range(1, 13):
    # How can I rewrite the following two lines?
    for line in Monthly(month):
      yield line
  yield YEARLY_FOOTER

def Monthly(month):
  yield MONTHLY_HEADER
  for day in range(31):  # Yes, this is wrong
    yield 'Day %d' % day
  yield MONTHLY_FOOTER

也许有更好的方法来重写这整个方法？

Answer 1

import itertools

def Yearly(year):
  return itertools.chain(*[(YEARLY_HEADER,)] + 
                         [Monthly(m) for m in range(1, 13)] + 
                         [(YEARLY_FOOTER,)])

基本上,使用YEARLY_HEADER和YEARLY_FOOTER进入迭代器,它们可以与月度迭代器链接.