汇总列表中的值

Question

我想添加相同ID的值

例如：在以下数据中，＆＃39; 6＆＃39;有两个值('6', 0.8556180596351624)和('6', 0.864041805267334)。

我想总结一下('6', 1.7196598649025)

的值

[('6', 0.8556180596351624), ('10', 0.8263003826141357), ('3', 0.8221487998962402), ('5', 0.8209285140037537), ('21', 0.8116759061813354), ('13', 0.798694372177124), ('16', 0.7894450426101685), ('17', 0.788898766040802), ('2', 0.7756567001342773), ('9', 0.7618461847305298), ('6', 0.864041805267334)

我怎么能这样做？建议请。

Answer 1

使用collections.defaultdict根据项目的第一个值对项目进行分类，然后将重复项目的第二个值相加：

In [22]: from collections import defaultdict

In [24]: d = defaultdict(int)

In [25]: lst = [('6', 0.8556180596351624), ('10', 0.8263003826141357), ('3', 0.8221487998962402), ('5', 0.8209285140037537), ('21', 0.8116759061813354), ('13', 0.798694372177124), ('16', 0.7894450426101685), ('17', 0.788898766040802), ('2', 0.7756567001342773),   ]

In [26]: for i, j in lst:
   ....:     d[i] += j
   ....:     

In [27]: d.items()
Out[27]: 
[('10', 0.8263003826141357),
 ('13', 0.798694372177124),
 ('21', 0.8116759061813354),
 ('17', 0.788898766040802),
 ('16', 0.7894450426101685),
 ('3', 0.8221487998962402),
 ('2', 0.7756567001342773),
 ('5', 0.8209285140037537),
 ('6', 1.7196598649024963),
 ('9', 0.7618461847305298)]

Answer 2

假设您想要所有唯一值，我会使用defaultdict()：

import collections
d = ... your list ...
cd = collections.defaultdict(int)
for key, value in d: cd[key] += value
print cd["6"]

打印1.7196598649024963。