标签：none 返回 rom tps style 元组 tle href 默认
用于创建并返回一个新的字典。两个参数：第一个是字典的键，第二个（可选）是传入键的值，默认为None。 第一个值可以是字符串、列表、元祖、字典
#列表
>>> dict1 = dict.fromkeys([1,2,3])
>>> dict1
{1: None, 2: None, 3: None}
#元组
>>> dict1 = dict.fromkeys((1,2,3))
>>> dict1
{1: None, 2: None, 3: None}
#修改默认值
>>> dict2 = dict.fromkeys([1,2,3,],‘test‘)
>>> dict2
{1: ‘test‘, 2: ‘test‘, 3: ‘test‘}
>>> dict2 = dict.fromkeys([1,2,3,],10)
>>> dict2
{1: 10, 2: 10, 3: 10}
#需要注意！
>>> dict3 = dict.fromkeys([1,2,3],[‘one‘,‘two‘,‘three‘])
>>> dict3
{1: [‘one‘, ‘two‘, ‘three‘], 2: [‘one‘, ‘two‘, ‘three‘], 3: [‘one‘, ‘two‘, ‘three‘]}
>>> list1 = [7,8,7,8,9,10]
>>> set(list1)
{8, 9, 10, 7}
>>> list1 = [7,8,7,8,9,10]
>>> b = dict.fromkeys(list1)
>>> b
{7: None, 8: None, 9: None, 10: None}
>>> c = list(b.keys())
>>> c
[7, 8, 9, 10]
标签：none 返回 rom tps style 元组 tle href 默认
原文地址：https://www.cnblogs.com/XJT2018/p/11405410.html
