小编dja*_*eur的帖子

我不确定迭代嵌套字典的最有效方法是为每个日期打印每个水果的总值和良好值的矩阵.以下面的两个列表和字典为例:

fruits = ['apples','oranges','bananas']
harvest_dates = ['2011-07-23','2011-07-22','2011-07-21']

harvest_data = {
  'apples': {
    '2011-07-23': {
      'total': 100,
      'good': 80},
     '2011-07-22': {
       'total': 97,
       'good': 92},
     '2011-07-21': {
       'total': 90,
       'good': 85}
  },
  'oranges': {
    '2011-07-23': {
      'total': 86,
      'good': 82},
    '2011-07-22': {
      'total': 90, 
      'good': 75},
    '2011-07-21': {
      'total': 92,
      'good': 92}
  },
  'bananas': {
    '2011-07-23': {
      'total': 10,
      'good': 9},
    '2011-07-22': {
      'total': 12, 
      'good': 11},
    '2011-07-21': {
      'total': 9,
      'good': 9}
  }
}

我可以在python中轻松完成:

for fruit in fruits:
  for …