python学习Day2之数据结构

Posted 2020-10-22 amei1992

列表[list]：

列表是Python中最基本的数据结构，列表中每个元素都分配一个位置

列表也称之为数组，数组可分为一维数组，多维数组

#一维数组
list = [‘Denny‘,‘Jenny‘,‘Liming‘,‘Lilei‘,‘Hanmeimei‘]

#多维数组
 #二维数组
 list1=[1,2,3,4,[51,52,53,54],6,,78]

 #三维数组
 list2=[1,2,3,4,[xiaoming[18,175],xiaola# 列list = [‘吉娃娃1‘,‘吉娃娃2‘,‘吉娃娃3‘,‘吉娃娃4‘]

a1 = list[0]
a2 = list[1]
a3 = list[2]
a4 = list[3]

# 按下标取值标
print(‘第0个元素：‘,a1 )
print(‘第1个元素：‘,a2)
print(‘第2个元素：‘,a3)
print(‘第3个元素：‘,a4)

运行结果：
D:\Python\Miniconda3\python.exe
第0个元素： 吉娃娃1
第1个元素： 吉娃娃2
第2个元素： 吉娃娃3
第3个元素： 吉娃娃4
Process finished with exit code 0

　

列表的基本操作：增、删、改、查

增：

 1 # 增
 2 方式一：
 3 list = [‘Denny‘,‘Jenny‘,‘Lilei‘,‘Hanmeimei‘]
 4 #append默认在最后的位置添加元素
 5 list.append(‘Liming‘)
 6 print(list)
 7 
 8 运行结果：
 9 D:\Python\Miniconda3\python.exe 10 [‘Denny‘, ‘Jenny‘, ‘Lilei‘, ‘Hanmeimei‘, ‘Liming‘]
11 Process finished with exit code 0
12 
13 
14 方式二：
15 list = [‘Denny‘,‘Jenny‘,‘Lilei‘,‘Hanmeimei‘]
16 #在指定位置中填写下标
17 list.insert(2,‘Liming‘)
18 print(list)
19 
20 运行结果：
21 D:\Python\Miniconda3\python.exe 22 [‘Denny‘, ‘Jenny‘, ‘Liming‘, ‘Lilei‘, ‘Hanmeimei‘]
23 Process finished with exit code 0

删

# 删
方式一：
#删除指定位置的元素
list = [‘Denny‘,‘Jenny‘,‘Liming‘,‘Lilei‘,‘Hanmeimei‘]
del list[3]
print(list)

运行结果：
D:\Python\Miniconda3\python.exe 
[‘Denny‘, ‘Jenny‘, ‘Liming‘, ‘Hanmeimei‘]
Process finished with exit code 0


方式二：
list = [‘Denny‘,‘Jenny‘,‘Liming‘,‘Lilei‘,‘Hanmeimei‘]
#pop不写指定位置默认删除最后的元素
list.pop()
print(list)

运行结果：
D:\Python\Miniconda3\python.exe
[‘Denny‘, ‘Jenny‘, ‘Liming‘, ‘Lilei‘]
Process finished with exit code 0


方式三：
list = [‘Denny‘,‘Jenny‘,‘Liming‘,‘Lilei‘,‘Hanmeimei‘]
#pop也可以删除指定位置的元素
list.pop(1)
print(list)

运行结果：
D:\Python\Miniconda3\python.exe 
[‘Denny‘, ‘Liming‘, ‘Lilei‘, ‘Hanmeimei‘]
Process finished with exit code 0


方式四：
list = [‘Denny‘,‘Jenny‘,‘Liming‘,‘Lilei‘,‘Hanmeimei‘]
#remove删除指定元素
list.remove(‘Jenny‘)
print(list)

运行结果：
D:\Python\Miniconda3\python.exe 
[‘Denny‘, ‘Liming‘, ‘Lilei‘, ‘Hanmeimei‘]
Process finished with exit code 0


方式五：
list = [‘Denny‘,‘Jenny‘,‘Liming‘,‘Lilei‘,‘Hanmeimei‘]
#清空列表
list.clear()
print(list)

运行结果：
D:\Python\Miniconda3\python.exe 
[]
Process finished with exit code 0

改

#改
list = [‘Denny‘,‘Jenny‘,‘Liming‘,‘Lilei‘,‘Hanmeimei‘]
list[1] = ‘xiaoming‘
print(list)

运行结果：
D:\Python\Miniconda3\python.exe 
[‘Denny‘, ‘xiaoming‘, ‘Liming‘, ‘Lilei‘, ‘Hanmeimei‘]
Process finished with exit code 0

查

list = [‘Denny‘,‘Jenny‘,‘Liming‘,‘Lilei‘,‘Hanmeimei‘]
#根据下标进行查询
a = list[1]
#-1取最后一个元素
b = list[-1]
print(a)
print(b)

运行结果：
D:\Python\Miniconda3\python.exe 
Jenny
Hanmeimei
Process finished with exit code 0