python - 合并两个2D字典python

Question

我有两个 2D python 字典，我想获得一个 2D 字典，其中键是前两个字典键的并集，值是 1d 字典的串联。如果一维字典中存在重复键，我希望获得它们值的总和。

所以，假设我:

dict1 = { 1: {2: 0.1, 3: 0.3, 4: 0.4} , 
          2 :{1: 0.2, 3: 0.3, 4: 0.5} }
dict2 = { 2: {1: 0.1, 3: 0.8, 5: 0.4} , 
          3 :{1: 0.2, 2: 0.8, 4: 0.5} }

我期望的是:

merged_dict = { 1: {2: 0.1, 3: 0.3, 4: 0.4} , 
                2 :{1: 0.3, 3: 1.1, 4: 0.5 , 5: 0.4} , 
                3: {1: 0.2, 2: 0.8, 4: 0.5} }

我目前使用的是 python 3.2.3

Answer 1

这里没什么特别的，但你总是可以做类似的事情:

merged_dict = dict1.copy()

for key, val in dict2.iteritems():
    if key not in dict1:
        merged_dict[key] = val
    else:
        for key2, val2 in val.iteritems():
            if key2 not in dict1[key]:
                merged_dict[key][key2] = val2
            else:
                merged_dict[key][key2] += val2

(抱歉，这是 python 2.7)

此外，如果您想使用defaultdict:

from collections import defaultdict
merged_dict = defaultdict(dict)

for key, val in dict1.iteritems():
    merged_dict[key] = defaultdict(int, val)
for key, val in dict2.iteritems():
    if key not in merged_dict:
        merged_dict[key] = defaultdict(int, val)
    else:
        for key2, val2 in val.iteritems():
            merged_dict[key][key2] += val2