python增删改查,列表

Posted 2020-10-11

list增删改查

 1 # [1,2,‘c‘,‘dfas‘,True]
 2 #索引和切片。
 3 # li = [1,2,3,‘af‘,‘re‘,4,‘45‘]
 4 # print(l[0])
 5 # print(l[3])
 6 # print(l[-1])
 7 #切片：
 8 # print(li[0:3])
 9 # print(li[2:5])
10 # print(li[0:5:2])
11 # print(li[-2::-2])
12 # print(li[5:0:-2])
13 #苑昊
14 # li = [‘taibai‘,‘alex‘,‘wusir‘]
15 #1增加 append 在最后增加一个元素
16 # print(li.append(‘yuanhao‘))
17 # li.append([1,2,3,‘www‘])
18 # print(li)
19 # while True:
20 #     username = input(‘请输入员工姓名：‘)
21 #     if username.lower() == ‘q‘:break
22 #     li.append(username)
23 #     print(li)
24 #insert 插入
25 # li = [‘taibai‘,‘alex‘,‘wusir‘]
26 # li.insert(1,‘日天‘)
27 # print(li)
28 #extend 迭代的添加
29 # li.extend(‘q‘)
30 # li.extend(‘asdt‘)
31 # li.extend([1,2,3,‘www‘])
32 # print(li)
33 li = [‘taibai‘,‘alex‘,‘wusir‘,‘egon‘,‘hulu‘,‘jingnvshen‘]
34 #删除 pop 按照索引去删除，有返回值
35 name = li.pop(1)
36 # print(li)
37 # print(name)
38 #remove 按照元素去删除
39 # li.remove(‘alex‘)
40 # print(li)
41 #clear 清空列表
42 # li.clear()
43 # print(li)
44 #del
45 # li = [‘taibai‘,‘alex‘,‘wusir‘,‘egon‘,‘hulu‘,‘jingnvshen‘]
46 # del li[2:4]
47 # print(li)
48 # del li[0:4:2]
49 # print(li)
50 li = [‘taibai‘,‘alex‘,‘wusir‘,‘egon‘,‘hulu‘,‘jingnvshen‘]
51 #改 切片先删除，迭代着添加
52 # li[0] = ‘男神‘
53 # print(li)
54 # li[0:3] = ‘都是男人‘
55 # print(li)
56 li[:] = ‘都是男人‘
57 print(li)
58 # li[0:2] = [‘asd‘]
59 # print(li)
60 # li[0:2] = [‘asd‘,‘fdsa‘,123]
61 # print(li)
62 #查
63 # print(li[1:4])
64 # for i in li:
65 #     print(i)
66 # li = [‘taibai‘,‘taibai‘,‘wusir‘,‘egon‘,‘taibai‘,‘jingnvshen‘]
67 # del li
68 # print(li)

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列表的嵌套

 1 li = [1,2,5,‘taibai‘,‘yuanhao‘,[1,‘alex‘,3,],True]
 2 ‘‘‘
 3 # print(li[3])
 4 # print(li[3][3])
 5 # s = li[4].capitalize()
 6 # li[4] = s
 7 #li[4] = li[4].capitalize()
 8 # li[4] = ‘Yuanhao‘
 9 # print(li)
10 # s2 = li[4].replace(‘hao‘,‘日天‘)
11 # li[4] = s2
12 # li[4] = li[4][0:4] + ‘ritian‘
13 # print(li)
14 # l2 = li[5]
15 # li[5][0] = ‘文杰‘
16 # print(li)
17 ‘‘‘
18 li[5][1] = li[5][1].upper()
19 print(li)

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列表的其他方法

 1 # li = [1,2,3,1,‘a‘,1,‘4‘]
 2 #count 计数
 3 # print(li.count(‘fasd‘))
 4 li = [2,3,1,5,6,8,9,7,4,10]
 5 #sort 正序排序
 6 # li.sort()
 7 # print(li)
 8 #li.sort(reverse=True) 倒叙排序
 9 # reverse 反转
10 # li.reverse()
11 # print(li)

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