Python,列表

1.list() 函数：--适用于所有类型的序列

print(list("Wang"))["W","a","n","g"]

2.修改列表元素

number=[1,2,3]number[1]=4print(number)[1,4,3]

3.删除元素

name=["wang","zhong"]del name[1]print(name)["wang"]

4.分片赋值

name=list("wamf")name[2:]=list("ng")print(name)["w","a","n","g"]

number=[1,2,3]number[0:2]=[7,8,9]print(number)[7,8,9,3]

5.列表方法

append()--列表末尾增加新对象

number=[1,2,3]number.append(4)print(number)[1,2,3,4]

count()--统计某个元素出现的次数

num=[[1,2],2,2,[2,3]]print(num.count(2))2

extend()--扩展原有序列，原地操作

a=[1,2,3]b=[4,5,6]a.extend(b)print(a)[1,2,3,4,5,6]

index()--查找某个元素在列表中的第一个位置

num=[1,2,3,4,5,6]print(num.index(3))2

insert()--插入元素到指定位置

num[1,2,3,4,5,6]num.insert(3,0)print(num)[1,2,3,0,4,5,6]

pop()--移除列表中某个位置的元素，默认是最后一个，并返回该元素的值,

num=[1,2,3]num.pop(1)2

remove()--移除列表中指定元素，没有返回值

num=[1,2,3]print(num.remove(1))[1,3]

reverse()--反向存放列表元素,改变列表，没有返回值  ||  reversed(num)

num=[1,2,3]print(num.reverse())[3,2,1]

sort()--对原来列表排序，改变原列表  || sorted(num)

num=[4,5,6,1,2,3]print(num.sort())[1,2,3,4,5,6]

6.高级排序

compare(x,y)  x<y-负 ；x>y-正；x=y-0；

sort()-参数 key reverse

x=["aaa","bb","c"]print(x.sort(key=len))["c","bb","aaa"]

x=[1,5,9,3,4,7]print(x.sort(reverse=True))[9,7,5,4,3,1]