Day2 - Python基础（列表，元组等）

Posted 2020-08-17

本节内容

1. 列表、元组操作
2. 字符串操作
3. 字典操作
4. 集合操作
5. 文件操作
6. 字符编码与转码 

1. 列表、元组操作

列表是我们最以后最常用的数据类型之一，通过列表可以对数据实现最方便的存储、修改等操作

 

定义列表示例

1 names = ["ZhangYang"," Guyun"," Xiangpeng"," XuLiangChen"]

通过下标访问列表中的元素，下标从0开始计数

1 >>> names[0]
2 ‘ZhangYang‘

 

切片示例1

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 #Author: nulige
 4 
 5 #!/usr/bin/env python
 6 # -*- coding:utf-8 -*-
 7 #Author: huzhihua
 8 
 9 names = "ZhangYang Guyun Xiangpeng XuLiangChen"
10 names = ["ZhangYang"," Guyun"," Xiangpeng"," XuLiangChen"]
11 
12 print(names)
13 print(names[0],names[2])
14 print(names[1:3])       #这就是切片（从0开始切，0就是ZhangYang）

执行结果：

1 [‘ZhangYang‘, ‘ Guyun‘, ‘ Xiangpeng‘, ‘ XuLiangChen‘]
2 ZhangYang  Xiangpeng
3 [‘ Guyun‘, ‘ Xiangpeng‘]

 

切片示例2

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 #Author: nulige
 4 
 5 names = "ZhangYang Guyun Xiangpeng XuLiangChen"
 6 names = ["ZhangYang"," Guyun"," Xiangpeng"," XuLiangChen"]
 7 
 8 print(names)
 9 print(names[0],names[2])
10 print(names[1:3])  #这就是切片（从0开始，取下标1至下标3之间的数字，包括1，不包括3）
11print(names[3])    #取第3个值，从0从始取
12print(names[-2])   #在不知道是多长的情况下，取出最后2个位置 
13print(names[-2:])  #要取最后面的值，把-1省略掉 
14print(names[0:3])  #取从0-3
15print(names[:3])   #如果是从头开始取，0可以忽略，跟上句效果一样

执行结果：

1 [‘ZhangYang‘, ‘ Guyun‘, ‘ Xiangpeng‘, ‘ XuLiangChen‘]
2 ZhangYang  Xiangpeng
3 [‘ Guyun‘, ‘ Xiangpeng‘]
4  XuLiangChen
5  Xiangpeng
6 [‘ Xiangpeng‘, ‘ XuLiangChen‘]
7 [‘ZhangYang‘, ‘ Guyun‘, ‘ Xiangpeng‘]
8 [‘ZhangYang‘, ‘ Guyun‘, ‘ Xiangpeng‘]

 

追加示例

1 #!/usr/bin/env python
2 # -*- coding:utf-8 -*-
3 #Author: nulige
4 
5 names = "ZhangYang Guyun Xiangpeng XuLiangChen"
6 names = ["ZhangYang"," Guyun"," Xiangpeng"," XuLiangChen"]
7 names.append("LeiHaidong")   #追加到最后一行
8 print(names)

执行结果：

1 [‘ZhangYang‘, ‘ Guyun‘, ‘ Xiangpeng‘, ‘ XuLiangChen‘, ‘LeiHaidong‘]

 

插入示例

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 #Author: nulige
 4 
 5 names = "ZhangYang Guyun Xiangpeng XuLiangChen"
 6 names = ["ZhangYang"," Guyun"," Xiangpeng"," XuLiangChen"]
 7 names.append("LeiHaidong")   #追加到最后一行
 8 names.insert(1,"nulige")     #插到那个位置 就写那个位置
 9 names.insert(3,"Xinzhiyu")   #插入3的位置，不能批量插入
10 print(names)

执行结果：

1 [‘ZhangYang‘, ‘nulige‘, ‘ Guyun‘, ‘Xinzhiyu‘‘ Xiangpeng‘, ‘ XuLiangChen‘, ‘LeiHaidong‘]

 

修改示例

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 #Author: nulige
 4 
 5 names = "ZhangYang Guyun Xiangpeng XuLiangChen"
 6 names = ["ZhangYang"," Guyun"," Xiangpeng"," XuLiangChen"]
 7 names.append("LeiHaidong")   #追加到最后一行
 8 names.insert(1,"nulige")     #插到那个位置 就写那个位置
 9 names.insert(3,"Xinzhiyu")   #插入3的位置，不能批量插入
10 names[2] ="XieDi" 　　　　　　 #修改
11 print(names)

执行结果：

1 [‘ZhangYang‘, ‘nulige‘, ‘XieDi‘, ‘Xinzhiyu‘, ‘ Xiangpeng‘, ‘ XuLiangChen‘, ‘LeiHaidong‘]

 

删除示例

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 #Author: nulige
 4 
 5 names = "ZhangYang Guyun Xiangpeng XuLiangChen"
 6 names = ["ZhangYang"," Guyun"," Xiangpeng"," XuLiangChen"]
 7 names.append("LeiHaidong")   #追加到最后一行
 8 names.insert(1,"Nulige")     #插到那个位置 就写那个位置
 9 names.insert(3,"Xinzhiyu")   #插入3的位置，不能批量插入
10 names[2] ="XieDi"
11 
12 #delete
13 names.remove("Nulige")   #删除Nulige
14 del names[1]
15 print(names)

执行效果：

删除前效果：

[‘ZhangYang‘, ‘Nulige‘, ‘XieDi‘, ‘Xinzhiyu‘, ‘ Xiangpeng‘, ‘ XuLiangChen‘, ‘LeiHaidong‘]

删除后效果：

1 [‘ZhangYang‘, ‘Xinzhiyu‘, ‘ Xiangpeng‘, ‘ XuLiangChen‘, ‘LeiHaidong‘]

index示例
查找XieDi的位置，并将找到的结果打印出来

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 #Author: nulige
 4 
 5 names = "ZhangYang Guyun Xiangpeng XuLiangChen"
 6 names = ["ZhangYang"," Guyun","XieDi"," Xiangpeng"," XuLiangChen"]
 7 
 8 # 查找XieDi的位置，并将找到的结果打印出来
 9 print(names)
10 print(names.index("XieDi"))           #找到XieDi
11 print(names[names.index("XieDi")])    #把他打印出来

执行结果：

1 [‘ZhangYang‘, ‘ Guyun‘, ‘XieDi‘, ‘ Xiangpeng‘, ‘ XuLiangChen‘]
2 2
3 XieDi

 

拷贝示例

1 #!/usr/bin/env python
2 # -*- coding:utf-8 -*-
3 #Author: nulige
4 
5 names = "ZhangYang Guyun Xiangpeng XuLiangChen"
6 names = ["ZhangYang"," Guyun","XieDi"," Xiangpeng"," XuLiangChen"]
7 
8 name_copy = names.copy()
9 print(name_copy)

执行结果：

1 [‘ZhangYang‘, ‘ Guyun‘, ‘XieDi‘, ‘ Xiangpeng‘, ‘ XuLiangChen‘]

copy真的这么简单么？

 

统计示例

#统计有两个XieDi

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 #Author: nulige
 4 
 5 names = "ZhangYang Guyun Xiangpeng XuLiangChen "
 6 names = ["ZhangYang"," Guyun","XieDi"," Xiangpeng"," XuLiangChen"]
 7 names.append("LeiHaidong")
 8 names.insert(1,"ChenRonghua")
 9 names.insert(3,"Xinzhiyu")   #插入
10 names[2] ="XieDi"            #修改
11 print(names)
12 print(names.count("XieDi"))

执行结果：

1 [‘ZhangYang‘, ‘ChenRonghua‘, ‘XieDi‘, ‘Xinzhiyu‘, ‘XieDi‘, ‘ Xiangpeng‘, ‘ XuLiangChen‘, ‘LeiHaidong‘]
2 2

 

清除示例

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 #Author: nulige
 4 
 5 names = "ZhangYang Guyun Xiangpeng XuLiangChen "
 6 names = ["ZhangYang"," Guyun","XieDi"," Xiangpeng"," XuLiangChen"]
 7 names.append("LeiHaidong")
 8 names.insert(1,"ChenRonghua")
 9 names.insert(3,"Xinzhiyu")   #插入
10 names[2] ="XieDi"            #修改
11 print(names)
12 print(names.count("XieDi"))
13 
14 #clear
15 names.clear()
16 print(names)

执行结果

1 [‘ZhangYang‘, ‘ChenRonghua‘, ‘XieDi‘, ‘Xinzhiyu‘, ‘XieDi‘, ‘ Xiangpeng‘, ‘ XuLiangChen‘, ‘LeiHaidong‘]
2 2
3 []   

 

反转示例1

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 #Author: nulige
 4 
 5 names = "ZhangYang Guyun Xiangpeng XuLiangChen "
 6 names = ["ZhangYang"," Guyun","XieDi"," Xiangpeng"," XuLiangChen"]
 7 names.append("LeiHaidong")
 8 names.insert(1,"ChenRonghua")
 9 names.insert(3,"Xinzhiyu")   #插入
10 names[2] ="XieDi"            #修改
11 print(names)
12 print(names.count("XieDi"))
13 
14 #reverse
15 names.reverse()
16 print(names)

执行结果：

1 [‘ZhangYang‘, ‘ChenRonghua‘, ‘XieDi‘, ‘Xinzhiyu‘, ‘XieDi‘, ‘ Xiangpeng‘, ‘ XuLiangChen‘, ‘LeiHaidong‘]    
2 2
3 [‘LeiHaidong‘, ‘ XuLiangChen‘, ‘ Xiangpeng‘, ‘XieDi‘, ‘Xinzhiyu‘, ‘XieDi‘, ‘ChenRonghua‘, ‘ZhangYang‘]    #对比第一行，反转过来了

 

反转示例2

 1 >>> names
 2 [‘Alex‘, ‘Tenglan‘, ‘Amy‘, ‘Tom‘, ‘Amy‘, 1, 2, 3]
 3 >>> names.sort() #排序
 4 Traceback (most recent call last):
 5   File "<stdin>", line 1, in <module>
 6 TypeError: unorderable types: int() < str()   #3.0里不同数据类型不能放在一起排序了，擦
 7 >>> names[-3] = ‘1‘
 8 >>> names[-2] = ‘2‘
 9 >>> names[-1] = ‘3‘
10 >>> names
11 [‘Alex‘, ‘Amy‘, ‘Amy‘, ‘Tenglan‘, ‘Tom‘, ‘1‘, ‘2‘, ‘3‘]
12 >>> names.sort()
13 >>> names
14 [‘1‘, ‘2‘, ‘3‘, ‘Alex‘, ‘Amy‘, ‘Amy‘, ‘Tenglan‘, ‘Tom‘]

 

排序示例

按ASCII码顺序进行排序的

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 #Author: nulige
 4 
 5 names = ["4ZhangYang"," #!Guyun","xXieDi"," Xiangpeng"," XuLiangChen"]
 6 print(names)
 7 
 8 #排序(sort)
 9 names.sort()
10 print(names)

执行结果：

1 [‘4ZhangYang‘, ‘ #!Guyun‘, ‘xXieDi‘, ‘ Xiangpeng‘, ‘ XuLiangChen‘]
2 [‘ #!Guyun‘, ‘ Xiangpeng‘, ‘ XuLiangChen‘, ‘4ZhangYang‘, ‘xXieDi‘]

 

扩展示例

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 #Author: nulige
 4 
 5 names = ["4ZhangYang"," #!Guyun","xXieDi"," Xiangpeng"," XuLiangChen"]
 6 print(names)
 7 
 8 names2 = [1,2,3,4]
 9 names.extend(names2)
10 print(names)

执行结果：

1 [‘4ZhangYang‘, ‘ #!Guyun‘, ‘xXieDi‘, ‘ Xiangpeng‘, ‘ XuLiangChen‘]
2 [‘4ZhangYang‘, ‘ #!Guyun‘, ‘xXieDi‘, ‘ Xiangpeng‘, ‘ XuLiangChen‘, 1, 2, 3, 4]

 

删除列表中的变量示例

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 #Author: nulige
 4 
 5 names = ["4ZhangYang"," #!Guyun","xXieDi"," Xiangpeng"," XuLiangChen"]
 6 print(names)
 7 
 8 names2 = [1,2,3,4]
 9 names.extend(names2)
10 del names2
11 print(names,names2)

执行结果：

会报错，因为找不到nemes2变量的值

1 Traceback (most recent call last):
2 [‘4ZhangYang‘, ‘ #!Guyun‘, ‘xXieDi‘, ‘ Xiangpeng‘, ‘ XuLiangChen‘]
3   File "D:/python/day2/name_test02.py", line 11, in <module>
4     print(names,names2)
5 NameError: name ‘names2‘ is not defined