python 合并字典，相同 key 的 value 相加

1.两个字典取并集，重点在于对相同key的value相加。

from collections import Counter

x = { 'apple': 1, 'banana': 2 }
y = { 'banana': 10, 'pear': 11 }

X,Y = Counter(x), Counter(y)
z = dict(X+Y)

[out] z = {'apple': 1, 'banana': 12, 'pear': 11}

 2.参考

• https://segmentfault.com/q/1010000000683968/