请教，关于python字典，合并相同值的键的实现方法

Question

{代码...} 我想 在字典dic_A中 将值相等的键合并,想要的到结果如下 {代码...} 请教一下，应该如何实现呢？ 谢谢。

天蓬老师 · Answer

Is it okay to look at it this way?

天蓬老师 · Answer

The questioner didn't make it clear which step to start the conversion from. If you work towards this goal from the beginning of the list, then this problem is actually not difficult.

from itertools import groupby
from functools import reduce

dic_a = {1: 7, 2: 7, 3: 9, 4: 8, 5: 8, 6: 8}

dica = dict([reduce(lambda v, e: (int(str(v[0])+str(e[0])), k), g) for k, g in 
groupby(dic_a.items(), lambda v: v[1])])
>>> dica
>>> {3: 9, 12: 7, 456: 8}

ringa_lee · Answer

python3

setdefault

>>> a = [1,2,3,4,5,6]
>>> b = [7,7,9,8,8,8]
>>> d={}
>>> for k,v in zip(b,a):
    d.setdefault(k,[]).append(v)

    
>>> d
{8: [4, 5, 6], 9: [3], 7: [1, 2]}
>>>