列表内置方法

列表类型内置方法

作用

用来存储多个爱好什么的

定义

 hobby=['paly','sleep']

优先掌握

1.按索引取值（正向取值+反向取值），即可存也可以取

  hobby_list = ['play', 'swimming', 'dancing','666']
  print(1, hobby_list[-1])
 hobby_list[-1] = '233'  # 索引修改
 print(2, hobby_list[-1])

1 666 2 233

2.切片

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

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

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

3.长度

 hobby_list = ['play', 'swimming', 'dancing','666']
 print(len(hobby_list))

4

4.in/not in

 hobby_list = ['play', 'swimming', 'dancing', '666']
 print('play' in hobby_list)  True

True

5.for 循环

 for hobby in hobby_list:  
     print(hobby)

play swimming dancing 666

6.del 删除

 del hobby_list[-1]
 print(hobby_list)

play swimming dancing

7.append() 追加

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

['play', 'swimming', 'dancing', '666', 'dapao-->piao']

需要掌握

1.count () 计数

 hobby_list = ['play', 'swimming', '666', 666, '666']
 print(hobby_list.count('666')) #对列表内的某一个元素计数

2

2.extend() 扩展

 hobby_list = ['play', 'swimming', '666', 666, '666']
 hobby_list.extend([1,2])
 print(hobby_list)

['play', 'swimming', '666', 666, '666', 1, 2]

3.clear() 清除

 hobby_list.clear()
 print(hobby_list)

[]

4.copy() 复制

 hobby_list2 = hobby_list.copy()  # 复制列表

5.pop() 删除（默认删除最后一个）

 hobby_list = ['play', 'swimming', '666', 666, '666']
 hobby_list.pop()
 print(hobby_list)

['play', 'swimming', '666', 666]

6.index() 索引

 print(hobby_list.index('play'))  # 索引
 print(hobby_list.index('play', 2, 4))  # 索引2-4内有没有该值

0 3

7.insert () 插入

 hobby_list = ['play', 'swimming', '666', 666, '666']
 hobby_list.insert(0, '1')  # 插入
 print(hobby_list)

['1', 'play', 'swimming', '666', 666, '666']

8.remove() 移除

 hobby_list = ['play', 'swimming', '666', 666, '666']
 hobby_list.remove('1')  # 移除
 print(hobby_list)

['play', '666', 666, '666']

9.reverse() 反转

 hobby_list = ['play', 'swimming', '666', 666, '666']
 hobby_list.reverse()
 print(hobby_list)

['666', 666, '666', 'swimming', 'play']

10.sort（），使用sort列表的元素必须是同类型的

 hobby_list = ['play', 'swimming', '666', '666']
 hobby_list.sort()
 print(hobby_list)

['666', '666', 'play', 'swimming']

存一个值or多个值：

多个值

有序or无序

有序

可变or不可变

可变数据类型