Python基础-列表_元组_字典_集合
本节内容
- 列表、元组操作
- 字符串操作
- 字典操作
- 集合操作
- 文件操作
- 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
1 #!/usr/bin/env python 2 # -*- coding:utf-8 -*- 3 #Author: nulige 4 5 names = ["4ZhangYang"," #!Guyun","xXieDi"," Xiangpeng"," XuLiangChen"] 6 names2 = names.copy() 7 print(names) 8 print(names2)
执行结果:
1 ['4ZhangYang', ' #!Guyun', 'xXieDi', ' Xiangpeng', ' XuLiangChen'] 2 ['4ZhangYang', ' #!Guyun', 'xXieDi', ' Xiangpeng', ' XuLiangChen']
拷贝示例2
1 #!/usr/bin/env python 2 # -*- coding:utf-8 -*- 3 #Author: nulige 4 5 names = ["4ZhangYang","#!Guyun","XiangPeng","ChenRonghua"] 6 names2 = names.copy() 7 print(names) 8 print(names2) 9 names[2] = "向鹏" 10 print(names)
执行结果：
1 ['4ZhangYang', '#!Guyun', 'XiangPeng', 'ChenRonghua'] 2 ['4ZhangYang', '#!Guyun', 'XiangPeng', 'ChenRonghua'] 3 ['4ZhangYang', '#!Guyun', '向鹏', 'ChenRonghua']
拷贝示例3
1、浅拷贝
示例1
浅拷贝就是浅浅的copy一层
1 #!/usr/bin/env python 2 # -*- coding:utf-8 -*- 3 #Author: nulige 4 #import copy 5 names = ["4ZhangYang","#!Guyun","XiangPeng",["alex","jack"],"ChenRonghua"] 6 names2 = names.copy() 7 print(names) 8 print(names2) 9 names[2] = "向鹏" 10 names[3][0] = "ALEXANDER" #注意：复制列表，只会复制一层 11 print(names) 12 print(names2)
执行结果:
1 ['4ZhangYang', '#!Guyun', 'XiangPeng', ['alex', 'jack'], 'ChenRonghua'] 2 ['4ZhangYang', '#!Guyun', 'XiangPeng', ['alex', 'jack'], 'ChenRonghua'] 3 ['4ZhangYang', '#!Guyun', '向鹏', ['ALEXANDER', 'jack'], 'ChenRonghua'] 4 ['4ZhangYang', '#!Guyun', 'XiangPeng', ['ALEXANDER', 'jack'], 'ChenRonghua'] #只拷贝了第一层，所以向鹏没有变
示例2
运行结果报错，后期再解决
1 #!/usr/bin/env python 2 # -*- coding:utf-8 -*- 3 #Author: nulige 4 5 import copy 6 7 person=['name',['a',100]] 8 #p1=copy.deepcopy(person) 9 p1=copy.copy(person) 10 p2=person[:] 11 p3=list(person)
结果省略...
示例3
1 #!/usr/bin/env python 2 # -*- coding:utf-8 -*- 3 #Author: nulige 4 5 person = ['name',['saving',100]] 6 p1=person[:] 7 p2=person[:] 8 p1[0]='alex' 9 p2[0]='fenjie' 10 p1[1][1]=50 #浅拷贝的作用，用于创建联合账号（100元，两人的两个账号各分一半，变成两个50元） 11 print(p1) 12 print(p2)
执行结果:
1 ['alex', ['saving', 50]] 2 ['fenjie', ['saving', 50]]
2、深拷贝
此实验还有点小问题，后期修改。
1 #!/usr/bin/env python 2 # -*- coding:utf-8 -*- 3 #Author: nulige 4 5 import copy 6 7 names = ["4ZhangYang","#!Guyun","XiangPeng",["alex","jack"],"ChenRonghua"] 8 #names2 = names.copy() 9 #names2 = copy.copy(names) 10 names2 = copy.deepcopy(names) 11 print(names) 12 print(names2) 13 names[2] = "向鹏" 14 names[3][0] = "ALEXANDER" #注意：复制列表，只会复制一层 15 print(names) 16 print(names2)
执行结果：省略......
列表循环
用for实现列表循环
1 #!/usr/bin/env python 2 # -*- coding:utf-8 -*- 3 #Author: nulige 4 5 #定义一个列表 6 names = ["4ZhangYang","#!Guyun","XiangPeng",["alex","jack"],"ChenRonghua"] 7 for i in names: 8 print(i)
执行结果：
1 4ZhangYang 2 #!Guyun 3 XiangPeng 4 ['alex', 'jack'] 5 ChenRonghua
跳着切片示例
1 #!/usr/bin/env python 2 # -*- coding:utf-8 -*- 3 #Author: nulige 4 5 #跳着切片 6 names = ["4ZhangYang","#!Guyun","XiangPeng",["alex","jack"],"ChenRonghua","Xuliangche"] 7 print(names[0:-1:2]) 8 print(names[::2]) 9 print(names[:]) #0到-1 10 11 for i in names: 12 print(i)
执行结果:
1 ['4ZhangYang', 'XiangPeng', 'ChenRonghua'] 2 ['4ZhangYang', 'XiangPeng', 'ChenRonghua'] 3 ['4ZhangYang', '#!Guyun', 'XiangPeng', ['alex', 'jack'], 'ChenRonghua', 'Xuliangche'] 4 4ZhangYang 5 #!Guyun 6 XiangPeng 7 ['alex', 'jack'] 8 ChenRonghua 9 Xuliangche
元组 (也叫不可变列表)
元组其实跟列表差不多，也是存一组数，只不是它一旦创建，便不能再修改，所以又叫只读列表。
语法
names = ("ales","jack","eric")
它只有两个方法，一个是count,一个是index。
示例：
1 #定义一个元组 2 tuple1 = (1, 2, '3', 4, '5') 3 # 定义了一个元组之后就无法再添加或修改元组中的元素 4 print tuple1[0] # 元组的元素都有确定的顺序。元组的索引也是以0为基点的 5 print tuple1[-1] # 负的索引从元组的尾部开始计数 6 print tuple1[1:3] # 元组也可以进行切片操作。对元组切片可以得到新的元组。 7 # 可以使用 in 运算符检查某元素是否存在于元组中。 8 print 1 in tuple1 # True 9 #使用for in 进行遍历元组 10 for item in tuple1: 11 print item 12 # 如果需要获取item的序号 可以使用下面的遍历方法： 13 for index in range(len(tuple1)): 14 print tuple1[index] 15 # 还可以使用内置的enumerate函数 16 for index, item in enumerate(tuple1): 17 print '%i, %s' % (index, item)
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
字符串操作
1 >>> a = 'alex' 2 >>> a [1] 3 'l' 4 >>> a[2] 5 'e' 6 7 #备注：列表不能直接赋值 8 9 >>> a[2] = '222' 10 Traceback (most recent call last): 11 File "<stdin>", line 1, in <module> 12 TypeError: 'str' object does not support item assignment
集合操作
集合的元素是不允许重复且无序的集合，集合就像是字典舍弃了值一样。
主要作用如下：
- 去重，把一个列表变成集合，就自动去重了
- 关系测试，测试两组数据之前的交集、差集、并集等关系
1 s = set([3,5,9,10]) #创建一个数值集合 2 3 t = set("Hello") #创建一个唯一字符的集合 4 5 6 a = t | s # t 和 s的并集 7 8 b = t & s # t 和 s的交集 9 10 c = t – s # 求差集（项在t中，但不在s中） 11 12 d = t ^ s # 对称差集（项在t或s中，但不会同时出现在二者中） 13 14 15 16 基本操作： 17 18 t.add('x') # 添加一项 19 20 s.update([10,37,42]) # 在s中添加多项 21 22 23 24 使用remove()可以删除一项： 25 26 t.remove('H') 27 28 29 len(s) 30 set 的长度 31 32 x in s 33 测试 x 是否是 s 的成员 34 35 x not in s 36 测试 x 是否不是 s 的成员 37 38 s.issubset(t) 39 s <= t 40 测试是否 s 中的每一个元素都在 t 中 41 42 s.issuperset(t) 43 s >= t 44 测试是否 t 中的每一个元素都在 s 中 45 46 s.union(t) 47 s | t 48 返回一个新的 set 包含 s 和 t 中的每一个元素 49 50 s.intersection(t) 51 s & t 52 返回一个新的 set 包含 s 和 t 中的公共元素 53 54 s.difference(t) 55 s - t 56 返回一个新的 set 包含 s 中有但是 t 中没有的元素 57 58 s.symmetric_difference(t) 59 s ^ t 60 返回一个新的 set 包含 s 和 t 中不重复的元素 61 62 s.copy() 63 返回 set “s”的一个浅复制
常用操作
交集(intersection)
两组列表中，取相同的值
1 #!/usr/bin/env python 2 # -*- coding:utf-8 -*- 3 #Author: nulige 4 5 list_1 = [1,4,5,7,3,6,7,9] 6 list_1 = set(list_1) 7 print(list_1,type(list_1)) 8 9 list_2 = ([2,6,0,66,22,8,4]) 10 print(list_1,list_2) 11 12 #交集 13 print( list_1.intersection(list_2) )
执行结果：
1 {1, 3, 4, 5, 6, 7, 9} <class 'set'> 2 {1, 3, 4, 5, 6, 7, 9} [2, 6, 0, 66, 22, 8, 4] 3 {4, 6}
并集（union)
两个列表合并成一个，去掉重复的值
1 #!/usr/bin/env python 2 # -*- coding:utf-8 -*- 3 #Author: nulige 4 5 list_1 = [1,4,5,7,3,6,7,9] 6 list_1 = set(list_1) 7 print(list_1,type(list_1)) 8 9 list_2 = ([2,6,0,66,22,8,4]) 10 print(list_1,list_2) 11 12 #并集 13 print(list_1.union(list_2))
执行结果：
1 {1, 3, 4, 5, 6, 7, 9} <class 'set'> 2 {1, 3, 4, 5, 6, 7, 9} [2, 6, 0, 66, 22, 8, 4] 3 {0, 1, 2, 3, 4, 5, 6, 7, 66, 9, 8, 22}
差集(difference)
只保留list1里面有的，list2中没有的值。
1 #!/usr/bin/env python 2 # -*- coding:utf-8 -*- 3 #Author: nulige 4 5 list_1 = [1,4,5,7,3,6,7,9] 6 list_1 = set(list_1) 7 print(list_1,type(list_1)) 8 9 list_2 = ([2,6,0,66,22,8,4]) 10 print(list_1,list_2) 11 12 #差集 13 print(list_1.difference(list_2))
14 print(list_2.difference(list_1))
执行结果：
1 {1, 3, 4, 5, 6, 7, 9} <class 'set'> 2 {1, 3, 4, 5, 6, 7, 9} [2, 6, 0, 66, 22, 8, 4] 3 {1, 3, 5, 7, 9}
4 {0,8,2,66,22}
对称差集（symmetric_difference）
把交集去掉了，留下的不是并集，把两个互相都没有的，取出来。
1 #!/usr/bin/env python 2 # -*- coding:utf-8 -*- 3 #Author: nulige 4 5 list_1 = [1,4,5,7,3,6,7,9] 6 list_1 = set(list_1) 7 8 list_2 = ([2,6,0,66,22,8,4]) 9 print(list_1,list_2) 10 11 12 #反向差集 13 print(list_1.symmetric_difference(list_2))
执行结果：
1 {1, 3, 4, 5, 6, 7, 9} [2, 6, 0, 66, 22, 8, 4] 2 {0, 1, 2, 66, 3, 5, 8, 7, 9, 22}
isdisjoint
判断有没有交集，如果有返回False，否则返回True
1 #!/usr/bin/env python 2 # -*- coding:utf-8 -*- 3 #Author: nulige 4 5 list_1 = [1,4,5,7,3,6,7,9] 6 list_1 = set(list_1) 7 8 list_2 = ([2,6,0,66,22,8,4]) 9 print(list_1,list_2) 10 11 #子集 12 list_3 = set([1,3,7]) 13 print(list_3.issubset(list_1)) 14 print(list_1.issubset(list_3)) 15 16 print("---------------------------------") 17 list_4 = set([5,6,8]) 18 print(list_3.isdisjoint(list_4))
执行结果：
1 {1, 3, 4, 5, 6, 7, 9} [2, 6, 0, 66, 22, 8, 4] 2 True 3 False 4 --------------------------------- 5 True
判断有没有交集，如果有返回False，否则返回True
1 #!/usr/bin/env python 2 # -*- coding:utf-8 -*- 3 #Author: nulige 4 5 list_1 = [1,4,5,7,3,6,7,9] 6 list_1 = set(list_1) 7 8 list_2 = ([2,6,0,66,22,8,4]) 9 print(list_1,list_2) 10 11 #子集 12 list_3 = set([1,3,7]) 13 print(list_3.issubset(list_1)) 14 print(list_1.issubset(list_3)) 15 16 print("---------------------------------") 17 list_4 = set([5,6,7,8]) 18 print(list_3.isdisjoint(list_4))
执行结果：
1 {1, 3, 4, 5, 6, 7, 9} [2, 6, 0, 66, 22, 8, 4] 2 True 3 False 4 --------------------------------- 5 False
子集(issubset)
1 #!/usr/bin/env python 2 # -*- coding:utf-8 -*- 3 #Author: nulige 4 5 list_1 = [1,4,5,7,3,6,7,9] 6 list_1 = set(list_1) 7 8 list_2 = ([2,6,0,66,22,8,4]) 9 print(list_1,list_2) 10 11 #差集 12 print( list_1.intersection(list_2)) 13 14 #子集 15 list_3 = set([1,3,7]) 16 print(list_3.issubset(list_1)) 17 print(list_1.issubset(list_3))
执行结果：
1 {1, 3, 4, 5, 6, 7, 9} [2, 6, 0, 66, 22, 8, 4] 2 {4, 6} 3 True 4 False
交集、并集、差集、对称差集另一种用法
1 #交集(intersection) 2 print(list_1 & list_2) 3 4 #并集 union 5 print(list_2 | list_1) 6 7 #差集 difference (in list 1 but not in list 2) 8 print(list_1 - list_2) 9 10 #对称差集 11 print(list_1 ^ list_2)
常用操作
1 #!/usr/bin/env python 2 # -*- coding:utf-8 -*- 3 #Author: nulige 4 5 list_1 = [1,4,5,7,3,6,7,9] 6 list_1 = set(list_1) 7 8 list_2 = ([2,6,0,66,22,8,4]) 9 print(list_1,list_2) 10 11 #添加一项(无序插入） 12 list_1.add(999) 13 print(list_1) 14 15 #添加多项 16 list_1.update([888,777,555]) 17 print(list_1) 18 19 #pop (删除） 20 # Remove and teturn an arbitrary set element. 21 # 删除一个，并返回一个任意的 22 print(list_1.pop()) 23 print(list_1.pop()) 24 print(list_1.pop()) 25 print(list_1.pop()) 26 27 #discard 28 print( list_1.discard(888) )
执行结果：
1 {1, 3, 4, 5, 6, 7, 9} [2, 6, 0, 66, 22, 8, 4] 2 {1, 3, 4, 5, 6, 7, 999, 9} 3 {1, 3, 4, 5, 6, 7, 999, 9, 777, 555, 888} 4 1 5 3 6 4 7 5 8 None
