python 列表操作
列表的基本操作示例展示:
append
功能:列表追加元素
name = ['sd','dfdf','drer']
name.append('sdsd')
返回结果:name
['sd', 'dfdf', 'drer', 'sdsd']
clear
功能:情况列表元素
name = ['sd','dfdf','drer']
name.clear()
返回结果:name
[]
copy
功能:浅拷贝,即只拷贝第一层的元素
name = ['sd','dfdf','drer']
li = ['ssd']
li = name.copy()
返回结果:li
['sd', 'dfdf', 'drer']
name = ['sd','dfdf','drer',['sddss','sdsdsd']]
li = ['ssd']
li = name.copy()
返回结果:li
['sd', 'dfdf', 'drer', ['sddss', 'sdsdsd']]
count
功能:统计列表指定元素个数
name = ['sd','dfdf','drer',['sddss','sdsdsd']]
name.count('sd')
返回结果:1
li = ['sd','sdsds',['sd','dffdg',],]
li.count('sd') #只统计第一层的元素个数
返回结果:1
extend
功能:追加字符元素或列表元素
name = ['sd','dfdf','drer',['sddss','sdsdsd']]
li = ['sd','sdsds',['sd','dffdg',],]
name.extend('ss')
返回结果:name
['sd', 'dfdf', 'drer', ['sddss', 'sdsdsd'], 's', 's']
name.extend('d')
返回结果:name
['sd', 'dfdf', 'drer', ['sddss', 'sdsdsd'], 's', 's', 'd']
name.extend(li)
返回结果:name
['sd', 'dfdf', 'drer', ['sddss', 'sdsdsd'], 's', 's', 'd', 'sd', 'sdsds', ['sd', 'dffdg']]
index
功能:定位列表中某元素
name = ['sd','dfdf','drer',['sddss','sdsdsd']]
name.index('sd')
返回结果:0
name.index('drer')
返回结果:2
返回结果:name.index('dr') #当出现某元素不在列表中的时候会直接报错
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ValueError: 'dr' is not in list
insert
功能:在指定索引位置的元素前面插入新的元素
name = ['sd','dfdf','drer',['sddss','sdsdsd']]
name.insert(3,'sd')
返回结果:name
['sd', 'dfdf', 'drer', 'sd', ['sddss', 'sdsdsd']]
pop
功能:删除指定索引值的元素,返回值为当前删除的元素的值。不指定索引值,默认删除最后一个元素
name = ['sd','dfdf','drer',['sddss','sdsdsd']]
name.pop(3)
返回结果:'sd'
remove
功能:删除列表中指定的元素
name = ['sd','dfdf','drer',['sddss','sdsdsd']]
name.remove('sd')
name
返回结果:['dfdf', 'drer', ['sddss', 'sdsdsd']]
reverse
功能:用于反向列表中元素。
name = ['sd','dfdf','drer',['sddss','sdsdsd']]
name.reverse()
name
返回结果:[['sddss', 'sdsdsd'], 'drer', 'dfdf', 'sd']
sort
功能:对单层列表进行元素的排序
name = ['sd','dfdf','drer',]
name.sort()
name
返回结果:['dfdf', 'drer', 'sd']
name = ['sd','dfdf','drer',['sddss','sdsdsd']]
name.sort() #报错的
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
@南非波波
github:https://github.com/swht