字典的 Python 列表理解示例

Question

I have the following script:

dict_class = dict()
for p in points:
    dict_class[p.class] = dict_class.get(p.class, 0) + 1

print dict_class
{1: 1314, 2: 1050}

其中“points”是一个值列表。我的问题是，是否可以转换字典的列表推导式以加快我的代码速度？

Answer 1

from collections import Counter 
from operator import attrgetter
Counter(map(attrgetter("class"),points))