Python学习随笔_2_基础：列表、元组
2021-07-12 13:04
标签：学习 根据 art eve 操作 display 数据 元组 一个 列表是Python 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。 返回元素第一次出现的下标。 Why? Becase：学习引用后解释，目前记住浅copy时：copy1修改嵌套列表时，copy2同时被修改。 一对夫妻，维护同一个银行账户！虽然实际开发中绝对不会这么做。。。 可能还有其他应用场景，但是我没想到。（就连这个也是别处看到的。。。） 元组（tuple）跟列表类似，也是存一组数据，只不是它一旦创建，便不能再修改，所以又叫只读列表。 有且仅有的两个方法，如下： 好，元组学完了。 需求（该练习选自http://www.cnblogs.com/alex3714/articles/5717620.html）: Python学习随笔_2_基础：列表、元组 标签：学习 根据 art eve 操作 display 数据 元组 一个 原文地址：https://www.cnblogs.com/104cz/p/9547259.html一、列表
1、定义列表
1 names = ["Cz","Cao","Zhang","Hui","Yang"]
2 print(names)
2、元素访问：通过下标
1 >>> names = ["Cz","Cao","Zhang","Hui","Yang"]
2 >>> names[0]
3 ‘Cz‘
4 >>> names[1]
5 ‘Cao‘
6 >>> names[-1]
7 ‘Yang‘
3、切片访问
1 >>> names = ["Cz","Cao","Zhang","Hui","Yang","Xiang","Xin"]
2 >>> names[1:3] #切片取值为[a,b)区间
3 [‘Cao‘, ‘Zhang‘]
4 >>> names[:3] #默认从头开始取值
5 [‘Cz‘, ‘Cao‘, ‘Zhang‘]
6 >>> names[-3:-1] #切片也能倒取
7 [‘Yang‘, ‘Xiang‘]
8 >>> names[-3:] #若倒取想获得最后一个值，只能用默认值
9 [‘Yang‘, ‘Xiang‘, ‘Xin‘]
10 >>> names[:4:2] #步长为2，取值
11 [‘Cz‘, ‘Zhang‘]
4、追加元素
1 >>> names = ["Cz","Cao","Zhang","Hui","Yang","Xiang","Xin"]
2 >>> names.append(‘New_person‘)
3 >>> print(names)
4 [‘Cz‘, ‘Cao‘, ‘Zhang‘, ‘Hui‘, ‘Yang‘, ‘Xiang‘, ‘Xin‘, ‘New_person‘]
5、插入元素
1 >>> names = ["Cz","Cao","Zhang","Hui","Yang","Xiang","Xin"]
2 >>> names.insert(1,‘New_person‘)
3 >>> names
4 [‘Cz‘, ‘New_person‘, ‘Cao‘, ‘Zhang‘, ‘Hui‘, ‘Yang‘, ‘Xiang‘, ‘Xin‘]
6、修改元素
1 >>> names
2 [‘Cz‘, ‘New_person‘, ‘Cao‘, ‘Zhang‘, ‘Hui‘, ‘Yang‘, ‘Xiang‘, ‘Xin‘]
3 >>> names[1] = ‘Old_person‘
4 >>> names
5 [‘Cz‘, ‘Old_person‘, ‘Cao‘, ‘Zhang‘, ‘Hui‘, ‘Yang‘, ‘Xiang‘, ‘Xin‘]
7、删除元素
1 >>> names
2 [‘Cz‘, ‘Old_person‘, ‘Cao‘, ‘Zhang‘, ‘Hui‘, ‘Yang‘, ‘Xiang‘, ‘Xin‘]
3 >>> del names[1] #删除指定下标元素
4 >>> names
5 [‘Cz‘, ‘Cao‘, ‘Zhang‘, ‘Hui‘, ‘Yang‘, ‘Xiang‘, ‘Xin‘]
6 >>> names.remove(‘Xiang‘) #删除指定元素
7 >>> names
8 [‘Cz‘, ‘Cao‘, ‘Zhang‘, ‘Hui‘, ‘Yang‘, ‘Xin‘]
9 >>> names.pop() #删除最后一个元素
10 ‘Xin‘
11 >>> names
12 [‘Cz‘, ‘Cao‘, ‘Zhang‘, ‘Hui‘, ‘Yang‘]
8、获取下标
1 >>> names
2 [‘Cz‘, ‘Cao‘, ‘Zhang‘, ‘Hui‘, ‘Yang‘]
3 >>> names.index(‘Zhang‘)
4 2
9、统计元素出现次数
1 >>> names
2 [‘Cz‘, ‘Cao‘, ‘Zhang‘, ‘Hui‘, ‘Yang‘, ‘Cz‘]
3 >>> names.count("Cz")
4 2
10、拓展：追加列表
1 num = [1,2,3]
2 >>> names.extend(num)
3 >>> names
4 [‘Cz‘, ‘Cao‘, ‘Zhang‘, ‘Hui‘, ‘Yang‘, ‘Cz‘, 1, 2, 3]
11、列表排序、反转
1 >>> names
2 [‘Cz‘, ‘Cao‘, ‘Zhang‘, ‘Hui‘, ‘Yang‘, ‘Cz‘, 1, 2, 3]
3 >>> names.sort()
4 Traceback (most recent call last):
5 File "
12、列表copy
1 >>> import copy
2 >>> copy1 = ["aa","bb",["ee","ff"],"cc","dd"]
3 >>> copy2 = copy.copy(copy1) #浅copy
4 >>> copy3 = copy.deepcopy(copy1) #深copy
5 >>> copy1[1] = "bbb"
6 >>> copy1[2][0] = "eee"
7 >>> copy1
8 [‘aa‘, ‘bbb‘, [‘eee‘, ‘ff‘], ‘cc‘, ‘dd‘]
9 >>> copy2
10 [‘aa‘, ‘bb‘, [‘eee‘, ‘ff‘], ‘cc‘, ‘dd‘]
11 >>> copy3
12 [‘aa‘, ‘bb‘, [‘ee‘, ‘ff‘], ‘cc‘, ‘dd‘]
二、一个好玩但不太实用的列表copy例子
1 >>> import copy
2 >>> person = [‘name‘,[‘saving‘,‘100‘]]
3 >>> p1 = person[:]
4 >>> p2 = person[:]
5 >>> p1
6 [‘name‘, [‘saving‘, ‘100‘]]
7 >>> p2
8 [‘name‘, [‘saving‘, ‘100‘]]
9 >>> p1[0] = ‘cz‘
10 >>> p2[0] = ‘zhang‘
11 >>> p1
12 [‘cz‘, [‘saving‘, ‘100‘]]
13 >>> p2
14 [‘zhang‘, [‘saving‘, ‘100‘]]
15 >>> p1[1][1] = 50 #其中一方花了50
16 >>> p1
17 [‘cz‘, [‘saving‘, 50]]
18 >>> p2
19 [‘zhang‘, [‘saving‘, 50]]
三、元组
1 >>> names = (‘cz‘,‘zhang‘,‘cao‘)
2 >>> names.count(‘cz‘)
3 1
4 >>> names.index(‘cz‘)
5 0
四、练习
1 salary = int(input(‘Please input you salary: ‘))
2
3 print(‘‘‘This is a list of goods. Please choose!
4 Direct settlement after selection, do not return!
5 You can enter Q to leave!
6 Thank you!‘‘‘)
7
8 commidity = [[1,‘IPhone‘,6188],[2,‘Honer‘,2188],[3,‘Book‘,58],[4,‘Computers‘,7888],[5,‘Water‘,2],[6,‘CPU_I7‘,3288]]
9 shopping_car = []
10
11 stat = ‘0‘
12
13 while stat != ‘Q‘:
14 for comm in commidity:
15 print(comm[0],‘ ‘,comm[1],‘ ‘,comm[2])
16
17 stat = input(‘Please input you selection: ‘)
18
19 if stat == ‘Q‘:
20 break
21
22 if salary >= commidity[int(stat)-1][2]:
23 shopping_car.append(commidity[int(stat)-1])
24 salary = salary-commidity[int(stat)-1][2]
25 print(‘Choose success！‘)
26
27 if salary ]:
28 print(‘Sorry, your credit is running low!‘)
29
30 print(‘‘‘Your balance is：{_salary}.
31 You have purchased the following commodities:‘‘‘.format(_salary=salary))
32 for shop in shopping_car:
33 print(shop[0],‘ ‘,shop[1],‘ ‘,shop[2])
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