python-第01章05章节-列表使用

1.列表简单的增删改查，反转，排序

#如果想存储很多信息，可以存储和改写，需要数据类型为列表
names = ["han","wang","liu" ,"hanjiali","han" ]
print(names[0],names[3])
#假如列表很多人，一起取中间两个人
print(names[1:3])#切片，这个格式为左闭右开，顾头不顾尾
#不知道有多长，但是取最后一个，怎么取
print(names[-1])
#想取出最后两个值
print(names[-2:])#想取出最后一个，但是不顾后面的，所以默认就可以
#人太少，想要放值（增）
   #1,直接写进去
names = ["han","wang","liu" ,"hanjiali"]
names.append("zhang" )
   #2，想插入放名字,不能批量插入
names.insert(1,"wanglong")#写想插入的位置，加插入的名字
print(names)
#想要改名字
names[2] = 'luojia'
print(names)
#删除
#1.
names.remove("han")
#2.
del names[1]
print(names)
#3.
names.pop()#删除最后一个
name.pop(1)#= del names[1]
#想要找人,前提列表很长
#1.将名字传给列表，找名字
print(names[names.index("liu")])
#2.重名的人，怎么查找
print(name.count("han"))
#清空表格
print(names.clear())
#反转列表
names.reverse()
#排序
names.sort()
#
name = [1,2,3,4,5]
names.extend(name)
print(names,name)

 2.列表的copy(浅copy,深copy)

#copy的用法,只cope第一层，为浅cope
names = ["han","wang","liu","hanjiali","han" ]

name2 = names.copy()
names[2] = "yu"
print(names)
print(name2)

 运行结果：

['han', 'wang', 'yu', 'hanjiali', 'han']
['han', 'wang', 'liu', 'hanjiali', 'han']

深copy

import copy
names = ["han","wang","liu","hanjiali","han" ]
name2 = copy.deepcopy(names)
print(names)
print(name2)
name1 = ["han","wang","liu","hanjiali","han" ]
name1[3] = "马瑞龙"
name3 = copy.deepcopy(name1)

print(name1)
print(name3)

 运行结果：

['han', 'wang', 'liu', 'hanjiali', 'han']
['han', 'wang', 'liu', 'hanjiali', 'han']
['han', 'wang', 'liu', '马瑞龙', 'han']
['han', 'wang', 'liu', '马瑞龙', 'han']

 3.列表跳着打印

names = ["han","wang","liu","hanjiali","han" ]
print(names[0:5:2])
for i in names:
    print(i)

 0和-1可以都去掉print(names[::2])

运行结果：

['han', 'liu', 'han']
han
wang
liu
hanjiali
han