python之列表

list列表:

 1 # li = [11, 22, 33, 22, 44]
 2 # 参数
 3 # 1. 原来值最后追加
 4 # 对象.方法(..)   # li对象调用append方法
 5 # li.append(5)
 6 # li.append("alex")
 7 # li.append([1234,2323])
 8 # print(li)
 9 # 2 清空列表
10 # li.clear()
11 # print(li)
12 
13 # 3 拷贝,浅拷贝
14 # v = li.copy()
15 # print(v)
16 # 4. 计算元素出现的次数
17 # v = li.count(22)
18 # print(v)
19 
20 # # 5. 扩展原列表,参数:可迭代对象
21 # li = [11, 22, 33, 22, 44]
22 # li.append([9898,"不得了"])
23 # print(li)
24 # [11, 22, 33, 22, 44, [9898, '不得了']]
25 
26 # li.extend([9898,"不得了"])
27 # for i in [9898,"不得了"]:
28 #     li.append(i)
29 # [11, 22, 33, 22, 44, 9898, '不得了']
30 #
31 # li.extend("不得了")
32 # print(li)
33 
34 # 6. 根据值获取当前值索引位置(左边优先)
35 # li = [11, 22, 33, 22, 44]
36 # v= li.index(22)
37 # print(v)
38 
39 # 7. 在指定索引位置插入元素
40 # li = [11, 22, 33, 22, 44]
41 # li.insert(0,99)
42 # print(li)
43 
44 # 8、 删除某个值(1.指定索引;2. 默认最后一个),并获取删除的值
45 # li = [11, 22, 33, 22, 44]
46 # v = li.pop()
47 # print(li)
48 # print(v)
49 
50 # li = [11, 22, 33, 22, 44]
51 # v = li.pop(1)
52 # print(li)
53 # print(v)
54 # 9. 删除列表中的指定值,左边优先
55 # li = [11, 22, 33, 22, 44]
56 # li.remove(22)
57 # print(li)
58 # PS: pop remove del li[0]    del li[7:9]   clear
59 
60 # 10 将当前列表进行翻转
61 # li = [11, 22, 33, 22, 44]
62 # li.reverse()
63 # print(li)
64 
65 # 11 列表的排序
66 li = [11,44, 22, 33, 22]
67 li.sort()
68 # li.sort(reverse=True)
69 print(li)
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 相关操作:

 1 # 修改
 2 # li[1] = 120
 3 # print(li)
 4 # li[1] = [11,22,33,44]
 5 # print(li)
 6 
 7 # 删除,第一种方式
 8 # del li[1]
 9 # print(li)
10 ############## 7 切片
11 # 修改
12 # li[1:3] = [120,90]
13 # print(li)
14 # 删除
15 # del li[2:6]
16 # print(li)
17 
18 # 8 in 操作
19 # li = [1, 12, 9, "age", ["石振文", ["19", 10], "庞麦郎"], "alex", True]
20 # v1 = "石振文" in li
21 # print(v1)
22 # v2 = "age" in li
23 # print(v2)
24 ###### 列表中的元素,
25 
26 # 9 操作
27 # li = [1, 12, 9, "age", ["石振文", ["19", 10], "庞麦郎"], "alex", True]
28 # print(li[4][1][0])
29 # li[4][1][0]
30 # [1]
31 
32 # li = [1, 12, 9, "age", ["石振文", ["19", 10], "庞麦郎"], "alex", True]
33 
34 # s = "pouaskdfauspdfiajsdkfj"
35 # s = 123
36 # a = "123"
37 # int(a)
38 # a = 123
39 # str(a)
40 # 10 转换
41 # 字符串转换列表   li =  list("asdfasdfasdf"), 内部使用for循环
42 # s = "pouaskdfauspdfiajsdkfj"
43 # new_li = list(s)
44 # print(new_li)
45 
46 # 列表转换成字符串,
47 # 需要自己写for循环一个一个处理: 既有数字又有字符串
48 # li = [11,22,33,"123","alex"]
49 # r = str(li) # '[11,22,33,"123","alex"]'
50 # print(r)
51 # s = ""
52 # for i in li:
53 #     s = s + str(i)
54 # print(s)
55 # 直接使用字符串join方法:列表中的元素只有字符串
56 # li = ["123","alex"]
57 # v = "".join(li)
58 # print(v)
59 
60 ### 补充:字符串创建后,不可修改
61 # v = "alex"
62 # v = v.replace('l','el')
63 # print(v)
64 
65 # li = [11,22,33,44]
66 # li[0]
67 # li[0] = 999
68 
69 # s = "alex"
70 # li[0]
71 # s[0] = "E"
72 
73 # li = [11,22,33,44]
74 # print(li)
75 # print(li)
76 # print(li)
77 # print(li)
78 # print(li)
79 # print(li)
80 # print(li)
81 # print(li)
82 # 列表,有序;元素可以被修改
83 
84 # 列表
85 # list
86 # li = [111,22,33,44]
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原文地址:https://www.cnblogs.com/sqy-yyr/p/9353995.html