列表类型内置方法

列表内置

1.作用

描述多个值,比如爱好

2.定义方式

hobby_list = ['play','swimming','dancing','666']
lt = list('nick')
print(lt)

3.内置方法

优先掌握

#1. 索引取值
hobby_list = ['play','swimming','dancing','666']
print(hobby_list[-1])

#2. 切片
print(hobby_list[:])   #['play','swimming','dancing','666']
print(hobby_list[::-1]) #从右到左 #['666','dancing','swimming','play']

#3.长度
print(len(hobby_list))

#4. in/not in
hobby_list = ['play','swimming','dancing','666']
print('play' in hoppy_list)   #True

#5. for循环

for hobby in hobby_list:
    print(hobby)
    
    
#6.del删除

del hobby_list[-1]
print(hobby_list)

#7.append()   #追加
hobby_list = ['play','swimming','dancing','666']
hobby_list.append('dapao-->piao')
print(hobby_list)

需要掌握

hobby_list = ['play','swimming','dancing','666']

hobby_list.count('666')  #对列表内的某一个元素计数  #2

hobby_list.exend([1,2,3,4])  #扩展列表  #Ctrl+鼠标左键
print(hobby_list)

hobby_list.clear()  #清除
print(hobby_list)   #[]

hobby_list.copy()  #复制列表

hobby_list[-1] = '233'
print(hobby_list)

hobby_list.pop()    #删除,默认删除最后一个
print(hobby_list)

hobby_list = ['play','swimming','dancing','666','666','666']
print(hobby_list.index('play'))
print(hobby_list.index('play',2,4))   #索引2-4内有没有该值


hobby_list.insert(0，‘1’)   #插入
print(hobby_list)


hobby_list.remove('1')   #移除
print(hobby_list)

hobby_list.reverse()   #反转
print(hobby_list)

hobby_list = [5,7,3,4,2,9,10]
hobby_list.sort()   #排序
print(hobby_list)  #[2,3,4,5,7,9,10]

4.存一个值还是多个值

多个值

5.有序or无序

有序

6.可变or不可变(重点)

可变

lis = [12,]

print(id(lis))

lis.append('12')

print(id(lis))