Python創建dict的幾種方法
阿新 • • 發佈:2018-03-21
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