创立字典
1.创立空字典
>>> dic = {}>>> type(dic)<type 'dict'>2.间接赋值创立
>>> dic = {'spam':1, 'egg':2, 'bar':3}>>> dic{'bar': 3, 'egg': 2, 'spam': 1}3.通过关键字dict和关键字参数创立
>>> dic = dict(spam = 1, egg = 2, bar =3)>>> dic{'bar': 3, 'egg': 2, 'spam': 1}4.通过二元组列表创立
list = [('spam', 1), ('egg', 2), ('bar', 3)]>>> dic = dict(list)>>> dic{'bar': 3, 'egg': 2, 'spam': 1}5.dict和zip联合创立
>>> dic = dict(zip('abc', [1, 2, 3]))>>> dic{'a': 1, 'c': 3, 'b': 2}6.通过字典推导式创立
>>> dic = {i:2*i for i in range(3)}>>> dic{0: 0, 1: 2, 2: 4}7.通过dict.fromkeys()创立
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'}8.其余
>>> list = ['x', 1, 'y', 2, 'z', 3]>>> dic = dict(zip(list[::2], list[1::2]))>>> dic{'y': 2, 'x': 1, 'z': 3}排序字典
names = ['Alice', 'Tom', 'Harry', 'Jerry', 'Mike'] scores = [[8, 6, 7 ], [6, 7, 5], [8, 6, 9], [5, 7, 4], [8, 10, 9]]dic = {}len1 =len(names)for i in range(len1): dic[names[i]]=sum(scores[i])# dic1 = dict(zip(names, scores))print(dic)# print(dic1)dic = dict(sorted(dic.items(), key=lambda x: x[1], reverse=True))print(dic)高阶函数
# forl = []for i in range(0, 11, 2): l.append(i*i)print(l)# filterl1 = list(filter(lambda x: x%2==0 and pow(x, 1/2) in range(11), range(101)))print(l1)# mapl2 = list(map(lambda x: x*x, range(0, 11, 2)))print(l2)# List derivationl3 = [i*i for i in range(0, 11, 2)]print(l3)# [0, 4, 16, 36, 64, 100]# [0, 4, 16, 36, 64, 100]# [0, 4, 16, 36, 64, 100]# [0, 4, 16, 36, 64, 100]一个奇怪的景象（生成二位数组）
m = n = 3test = [[0] * m] * nprint("test =", test)输入后果如下：test = [[0, 0, 0], [0, 0, 0], [0, 0, 0]]是不是看起来没有一点问题？
一开始我也是这么感觉的，认为是我其余中央用错了什么函数，后果这么一试：
m = n = 3test = [[0] * m] * nprint("test =", test)test[0][0] = 233print("test =", test)输入后果如下：
test = [[0, 0, 0], [0, 0, 0], [0, 0, 0]]test = [[233, 0, 0], [233, 0, 0], [233, 0, 0]]也就是说matrix = [array] * 3操作中，只是创立3个指向array的援用，所以一旦array扭转，matrix中3个list也会随之扭转。
生成二维数组利用列表生成式
from random import randintl = [[randint(0, 11) for i in range(5)] for j in range(5)]print(l)