Python简洁语法笔记

defaultdict

需要构造类似{k1: {v11, v12, v13, ...}, k2: {v21, v22, v23, ...}, ...}结构的数据时，可以用collections.defaultdict：

from collections import defaultdict


a = defaultdict(set())
for i in range(100):
    a[i].append('test1')
    a[i].append('test1')

逻辑选择语法

用and或or替换掉某些if else语句

a = 0
b = a if a else 0

b = a and 0


c = 1
d = c if not c else 1

d = c and 1