Question

我希望在词典中加上值的总和下面是我写的代码。

results = collections.defaultdict(dict)
for main, month, tot in list_data:
    d = results[main]
    d[month] = tot  
    d.setdefault('total', 0)
    d['total'] += tot
result_output = dict(results)

以上代码给出了以下输出：

{u'Apple': {'January': 17, 'February': 1, 'total': 19, 'March': 1}, 
 u'Oranges': {'total': 1, 'March': 1}, 
 u'Graphes': {'January': 24, 'February': 1, 'total': 66, 'March': 41}}

但我想要这样的输出：

{u'Apple': {'January': 17, 'February': 1, 'total': 19, 'March': 1}, 
 u'Oranges': {'total': 1, 'March': 1}, 
 u'Graphes': {'January': 24, 'February': 1, 'total': 66, 'March': 41, 'April': 1}, 
 u'grandtotal': {'January': 41 , 'February': 3, 'March': 43, 'April':1 }}

我只是想知道是否有人可以帮我解决这个问题。我真的很感激。

Answer 1

这个怎么样？（未测试）

from collections import defaultdict
from functools import partial

results = defaultdict(partial(defaultdict, int))
for main, month, tot in list_data:
    results[main][month] += tot
    results[main]["total"] += tot
    results[u"grandtotal"][month] += tot
result_output = dict((k, dict(v)) for k, v in results.items())

编辑：result_output现在有dict值而不是defaultdict值。

Answer 2

你可以尝试，而不是测试...

gt = collections.defaultdict(int)         # get a new dict
results = collections.defaultdict(dict) 
for main, month, tot in list_data: 
   d = results[main]
   d[month] = tot  
   gt[month]+=tot                         # populate it
   d.setdefault('total', 0)
   d['total'] += tot
 result_output = dict(results)
 results_output['grand_total'] = gt       # save it

Answer 3

所以你想要添加一个Grandtotal。

如果您从以下结构开始：

starting_data = {u'Apple': {'January': 17, 'February': 1, 'total': 19, 'March': 1}, 
                 u'Oranges': {'total': 1, 'March': 1}, 
                 u'Graphes': {'January': 24, 'February': 1, 'total': 66, 'March': 41}}

您可以执行类似

的操作

grand_total = defaultdict(int) # makes it default to 0
for fruit, fruitdict in starting_data.items():
    for month, total in fruitdict.items():
        grand_total[month] += total
starting_data[u'grand_total'] = dict(grand_total)

已经过测试并给出了

{u'Apple': {'February': 1, 'January': 17, 'March': 1, 'total': 19},
 u'Graphes': {'February': 1, 'January': 24, 'March': 41, 'total': 66},
 u'Oranges': {'March': 1, 'total': 1},
 u'grand_total': {'February': 2, 'January': 41, 'March': 43, 'total': 86}}

显然你不需要再次浏览列表并且可以更早地聚合;但我喜欢测试并且不知道输入数据的格式。

Answer 4

使用collections.Counter：

import collections

results = collections.Counter()

a = {u'Apple': {'January': 17, 'February': 1, 'total': 19, 'March': 1},
     u'Oranges': {'total': 1, 'March': 1},
     u'Graphes': {'January': 24, 'February': 1, 'total': 66, 'March': 41}}

for counts in a.values():
     results.update(counts)

print results # Counter({'total': 86, 'March': 43, 'January': 41, 'February': 2})

字典中的值的总和

4 个答案: