defaultdict如何获取列表中所有值的总和?

Nem*_* Ga 3 python

这是代码:

models = [Url1, Url2, Url3, Url4, Url5, Url6, Url7, Url8, Url9, Url10]
d = defaultdict(list)

for model in models:

    getids = model.objects.values_list('keyword', 'score')
    for kw, score in getids:
        d[kw].append(score)
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这使'd'输出:

defaultdict(<type 'list'>, {198: [-70, 0, 5, -70, 5, 5, 0, 0, -50, -70],     
199: [0, -70, -70, -70, -70, -70, -100, -70, -70, -70]})
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如何让它返回:

defaultdict({198: -245, 199: -660}) #sum of all numbers inside lists, returned as values to both keys.
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我尝试循环但是deafultdict似乎不像普通列表那样工作.

Lin*_*ios 6

试试这个:

d = defaultdict(int)

for model in models:

    getids = model.objects.values_list('keyword', 'score')
    for kw, score in getids:
        d[kw] += score
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  • 这里的关键是使用`int`作为默认工厂,以便您可以保持运行总和. (3认同)