Python 创建字典的多种方式

1.通过关键字dict和关键字参数创建
>>> dic = dict(spam = 1, egg = 2, bar =3)
>>> dic
{\'bar\': 3, \'egg\': 2, \'spam\': 1}

2.通过二元组列表创建
>>> list = [(\'spam\', 1), (\'egg\', 2), (\'bar\', 3)]
>>> dic = dict(list)
>>> dic
{\'bar\': 3, \'egg\': 2, \'spam\': 1}

3.dict和zip结合创建
>>> dic = dict(zip(\'abc\', [1, 2, 3]))
>>> dic
{\'a\': 1, \'c\': 3, \'b\': 2}

4.通过字典推导式创建
>>> dic = {i:2*i for i in range(3)}
>>> dic
{0: 0, 1: 2, 2: 4}

5.通过dict.fromkeys()创建
通常用来初始化字典, 设置value的默认值

>>> dic = dict.fromkeys(range(3), \'x\')
>>> dic
{0: \'x\', 1: \'x\', 2: \'x\'}

6.其他
>>> list = [\'x\', 1, \'y\', 2, \'z\', 3]
>>> dic = dict(zip(list[::2], list[1::2]))
>>> dic
{\'y\': 2, \'x\': 1, \'z\': 3}