推导式,其实就是将多行的循环语句放到一行写
# -*- coding: utf-8 -*- # 列表推导式 lst = [i for i in range(5)] print(lst) # [0, 1, 2, 3, 4] # 相当于 lst2 = list() for i in range(5): lst2.append(i) print(lst2) # [0, 1, 2, 3, 4] # 集合推导式 lst = [1, 2, 3, 3, 2, 4, 4] st = {i for i in lst if i % 2 == 0} print(st) # {2, 4} # 字典推导式 dct = {k: v for k, v in enumerate(range(5))} print(dct) # {0: 0, 1: 1, 2: 2, 3: 3, 4: 4}