列表类型内置方法(list)
1.作用
用来描述多个装备、多个爱好、多种状态等
2.定义
在[]里可以存放多个任意类型的值,逗号分隔元素
hobby_list = ['run','play','read']
hobby_list = list ['run','play','read']
print(f'my hobby_list:{hobby_list}')
# my hobby_list:['run','play','read']
3.常用操作+内置方法
**优先掌握**
1.按索引取值
2.切片(split)
3.长度(len)
4.成员运算(is/is not)
5.for循环
6.删除(del)
7.追加(append)
1.索引取值(正向取值+反向取值,既可以存也可以取)
# list之索引取值
hobby_list = ['play', 'swimming', 'dancing', '666']
print(1, hobby_list[-1])
hobby_list[-1] = '233' # 索引修改
print(2, hobby_list[-1])
2.切片(split)
# list之切片
print(hobby_list[:]) # ['play', 'swimming', 'dancing', '666']
print(hobby_list[::-1]) # 从右到左 # ['666', 'dancing', 'swimming', 'play']
# ['play', 'swimming', 'dancing', '233']
# ['233', 'dancing', 'swimming', 'play']
3.长度(len)
# list之长度
name_list = ['nick', 'jason', 'tank', 'sean']
print(f"len(name_list): {len(name_list)}")
# len(name_list): 4
4.成员运算(in/not in)
# list之成员运算in和not in
name_list = ['nick', 'jason', 'tank', 'sean']
print(f"'tank sb' in name_list: {'tank sb' in name_list}")
print(f"'nick handsome' not in name_list: {'nick handsome' not in name_list}")
# 'tank sb' in name_list: False
# 'nick handsome' not in name_list: True
5.循环(for)
# list之循环
name_list = ['nick', 'jason', 'tank', 'sean']
for name in name_list:
print(name)
##结果
nick
jason
tank
sean
6.删除(del)
# list之删除
name_list = ['nick', 'jason', 'tank', 'sean']
del name_list[2]
print(f"name_list: {name_list}")
# name_list: ['nick', 'jason', 'sean']
7.追加值(append)
# list之追加值
name_list = ['nick', 'jason', 'tank', 'sean']
name_list.append('tank sb')
print(f"name_list: {name_list}")
# name_list: ['nick', 'jason', 'tank', 'sean', 'tank sb']
**需要掌握**
1.insert(插入,在列表的某一个位置插入一个元素)
2.pop(删除元素.默认删除列表最后一个元素)
3.remove(移除元素)
4.count(计数.u哦你过来计数列表里面某一元素出现的次数)
5.index(索引.返回列表里某一元素的位置)
6.claar(清空列表)
7.copy(复制列表)
8.extend(继承,也就是两个列表何在一起)
9.reverse(反转列表的元素,从右到左进行排序)
10.sort(排序.默认升序排)
1.insert(插入元素)
hobby_list = ['run','play','read']
hobby_list.insert(1,'sleep')
print(hobby_list)
# ['run', 'sleep', 'play', 'read']
2.pop(删除元素)
# pop默认删除的是最后一个元素,但是也可以指定索引的位置
hobby_list = ['run','play','read']
hobby_list.pop()
print(hobby_list)
# ['run', 'play']
hobby_list = ['run','play','read']
hoppy_list.pop(0)
print(hobby_list)
# ['play','read']
3.remove(移除)
hobby_list = ['run','play','read']
hobby_list.remove('run')
print(hobby_list)
# ['play','read']
4.count(统计某一元素在列表出现的次数)
hobby_list = ['run','play','read']
print(hobby_list.count('run'))
# 1
5.index()
hobby_list = ['run','play','read']
print(hobby_list(play))
# 1
6.clear()
hobby_list = ['run','play','read']
hobby_list.clear()
print(hobby_list)
# []
7.copy()
hobby_list = ['run','play','read']
hobby_list2 = hobby_list.copy
print(hobbby_list2)
# ['run','play','read']
8.extend()
hobby_list = ['run','play','read']
hobby_list2 = ['sing']
hobby_list.extend(hobby_list2)
print(hobby_list)
# ['run', 'play', 'read', 'sing']
9.reverse()
hobby_list = ['run','play','read']
hobby_list.reverse()
print(hobby_list)
# ['read', 'play', 'run']
10.sort()
hobby_list = ['run','play','read']
hobby_list.sort()
print(hobby_list)
['play', 'read', 'run']
4.列表是存多个值的
5.列表是有序的
hobby_list = ['run','play','read']
print(id(hobby_list))
hobby_list[2] = 'sing'
print(id(hobby_list))
#结果
2855383215368
2855383215368