列表类型内置方法
一、列表类型内置方法(list)
- 用途:多个装备、多个爱好、多门课程、甚至多个女朋友
- 定义:[]内可以有多个任意类型的值.逗号分隔元素
# my_girl_friend = list([]'jason','tank','sean'])
my_girl_friend = ['jason','tank','sean']
print(my_girl_friend)
['jason', 'tank', 'sean']
l = list('hello nick')
print(l)
['h', 'e', 'l', 'l', 'o', ' ', 'n', 'i', 'c', 'k']
- 常用操作+内置方法:常用操作和内置方法分为优先掌握、需要掌握、其他操作三分部分。
一、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
# list 之索引取值
name_list = ['nick','jason','tank','sean']
name_list[0] = 'nick handsome'
# name_list(1000) = 'tank sb'#报错
print(name_list[0])
nick handsome
- 切片
# list之切片
name_list = ['nick','jason','tank','sean']
print(name_list[0:3:2])
['nick', 'tank']
- 长度len
# list之长度
name_list = ['nick','jason','tank','sean']
print(len(name_list))
4
- 成员运算in 和not in
#list之成员运算in 和not in
name_list = ['nick','jason','tank','sean']
print('nick handsome' in name_list)
print('tank sb' not in name_list)
False
True
- 追加值(append)
#list之追加值(append)
name_list = ['nick','jason','tank','sean']
name_list.append('nick handsome')
print(name_list)
['nick', 'jason', 'tank', 'sean', 'nick handsome']
- 删除
#list之删除
name_list = ['nick','jason','tank','sean']
del name_list[0]
print(name_list)
['jason', 'tank', 'sean']
- 循环
#list之循环
name_list = ['nick','jason','tank','sean']
for i in name_list:
print(i)
nick jason tank sean
二、需要掌握
- insert(添加)
- pop
- remove
- count
- index
- clear
- copy
- extend
- reverse
- sort
- insert()
# list之insert()
name_list = ['nick','jason','tank','sean']
name_list.insert(1,'handsome')
print(name_list)
['nick', 'handsome', 'jason', 'tank', 'sean']
- pop(默认删除最后一个)
# list之pop(),pop()默认删除最后一个元素
name_list = ['nick','jason','tank','sean']
print(name_list.pop(0))
print(name_list)
nick ['jason', 'tank', 'sean']
- remove(移除)
# list之remove()
name_list = ['nick', 'jason', 'tank', 'sean']
#print(name_list.remove('nick'))(当直接些这句代码时 返回none)
name_list.remove('nick')
print(name_list)
['jason', 'tank', 'sean']
- count()
# list之count()
name_list = ['nick','jason','tank','sean']
print(name_list.count('nick'))
1
- index()
# list之index()
name_list = ['nick','jason','tank','sean']
print(name_list.index('nick'))
0
- clear()
# list之clear()
name_list = ['nick','jason','tank','sean']
name_list.clear
print(name_list)
[]
- copy()
# list之copy()
name_list = ['nick','jason','tank','sean']
print(name_list.copy())
['nick', 'jason', 'tank', 'sean']
- extend(扩展)
# list之extend()
name_list = ['nick','jason','tank','sean']
name_list2 = ['nick handsome']
name_list.extend(name_list2)
print(name_list)
['nick', 'jason', 'tank', 'sean', 'nick handsome']
- reverse()
# list之reverse()
name_list = ['nick','jason','tank','sean']
name_list.reverse()
print(name_list)
['sean', 'tank', 'jason', 'nick']
- sort()
# list之sort(),使用sort列表的元素必须是同类型的
name_list = ['nick','jason'.'tank','sean']
name_list.sort()
print(name_list)
name_list0sort(reverse=True)
print(name_list)
['jason', 'nick', 'sean', 'tank'] ['tank', 'sean', 'nick', 'jason']
存一个值or多个值:多个在
有序or无序:有序
可变不可变:可变数据类型
hobby_list = ['read', 'run', 'girl']
print(f'first:{id(hobby_list)}')
hobby_list[2] = ''
print(f'second:{id(hobby_list)}')
first:4522187016 second:4522187016