根据关键字/值标准聚合字典数组中的某些值

Question

我有下面论坛帖子的JSON。创建每个论坛聚合正面/负面评级的JSON的Python方式是什么？

输入Json：

{"Posting_Stats":{
"Posts":[
{
"Date":"2020-03-29 12:41:00",
"Forum":"panorama",
"Positive":2,
"Negative":0
},
{
"Date":"2020-03-29 12:37:00",
"Forum":"web",
"Positive":6,
"Negative":0
},
{
"Date":"2020-03-29 12:37:00",
"Forum":"web",
"Positive":2,
"Negative":2
},...]}

输出应为：

{"Forum_Stats" : [{"Forum" : "panorama",
"Positive":2,
"Negative":0},
{"Forum" : "web",
"Positive":8,
"Negative":2},...]
}

]

Answer 1

想不出其他方法：

posts = inputData['Posting_Stats']['Posts']
postAggregator = {}
for post in posts:
try:
postAggregator[post['Forum']]['Positive'] += post.get('Positive',0)
postAggregator[post['Forum']]['Negative'] += post.get('Negative',0)
except KeyError:
postAggregator.update({post['Forum']:{"Positive":post.get('Positive',0), "Negative":post.get('Negative',0)}})
outputData = {"Forum_Stats": []}
for key, value in postAggregator.items():
outputData['Forum_Stats'].append({"Forum":key , "Positive":value['Positive'],"Negative":value['Negative']})
print(outputData)

输出：

{'Forum_Stats': [{'Forum': 'panorama', 'Positive': 2, 'Negative': 0}, {'Forum': 'web', 'Positive': 8, 'Negative': 2}]}

Answer 2

这可能是一种解决方法：

#taking the input in a dictionary
d = {"Posting_Stats":{
"Posts":[
{
"Date":"2020-03-29 12:41:00",
"Forum":"panorama",
"Positive":2,
"Negative":0
},
{
"Date":"2020-03-29 12:37:00",
"Forum":"web",
"Positive":6,
"Negative":0
},
{
"Date":"2020-03-29 12:37:00",
"Forum":"web",
"Positive":2,
"Negative":2
}]}}
#iterating over the values to get their some on the basis of forum as key
temp = {}
for i in d.get('Posting_Stats').get('Posts'):
if temp.get(i.get('Forum')) == None:
temp[i.get('Forum')] = {}
temp[i.get('Forum')]['Positive'] = 0
temp[i.get('Forum')]['Negative'] = 0
temp[i.get('Forum')]['Positive']+=i.get('Positive')
temp[i.get('Forum')]['Negative']+=i.get('Negative')

最后将输出转换为所需格式

output = [{'Forum': i , **temp[i] } for i in temp]
print(output)
#[{'Forum': 'panorama', 'Positive': 2, 'Negative': 0},
#{'Forum': 'web', 'Positive': 8, 'Negative': 2}]