1. 程式人生 > >Python創建dict的幾種方法

Python創建dict的幾種方法

range () OS style 元組 art 列表創建 pre clas

聲明:轉自CSDN (http://blog.csdn.net/csujiangyu/article/details/45176399)

1. 創建空字典

>>> dic = {}
>>> type(dic)
<type dict>

2.直接賦值創建

>>> dic = {spam:1, egg:2, bar:3}
>>> dic
{bar: 3, egg: 2, spam: 1}

3.通過關鍵字dict和關鍵字參數創建

>>> dic = dict(spam = 1, egg = 2, bar =3)
>>> dic {bar: 3, egg: 2, spam: 1}

4.通過二元組列表創建

>>> list = [(spam, 1), (egg, 2), (bar, 3)]
>>> dic = dict(list)
>>> dic
{bar: 3, egg: 2, spam: 1}

5.dict和zip結合創建

>>> dic = dict(zip(abc, [1, 2, 3]))
>>> dic
{a: 1, c: 3, b
: 2}

6.通過字典推導式創建

>>> dic = {i:2*i for i in range(3)}
>>> dic
{0: 0, 1: 2, 2: 4}

7.通過dict.fromkeys()創建

通常用來初始化字典, 設置value的默認值

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

8.其他

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

Python創建dict的幾種方法