python基础--列表list

1. 作用

python中的list类似数组，python最常见的数据类型，可以存储不同类型的数据。

2. 操作

创建列表

>>> l1 = ['Tommy', 'Laura', 'Andy']
>>> l1
['Tommy', 'Laura', 'Andy']
>>> l2 = [i for i in range(10)] 
>>> l2
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> l3 = ['Bill', 25, 'Teacher']
>>> l3
['Bill', 25, 'Teacher']
>>> 

利用索引进行访问，修改

>>> l1[1]
'Laura'
>>> l2[0]
0
>>> l1[1] = 'Maria'
>>> l1
['Tommy', 'Maria', 'Andy']
>>> l2[0] = 100
>>> l2
[100, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> 

列表添加元素append，插入元素insert

>>> l1
['Tommy', 'Maria', 'Andy']
>>> l1.append('Julia')
>>> l1
['Tommy', 'Maria', 'Andy', 'Julia']
>>> l2.append(l0)
>>> l2
[100, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
>>> l1.append(l2)
>>> l1
['Tommy', 'Maria', 'Andy', 'Julia', [100, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]]
>>> l2.insert(2, 20)
[100, 1, 20, 2, 3, 4, 5, 6, 7, 8, 9, 10]
>>> 

删除列表元素del，pop， remove， clear

>>> l3
['Bill', 25, 'Teacher']
>>> del l3[2] # 删除某一个元素
>>> l3
['Bill', 25]
>>> l3.pop() # 删除最后一个元素，也可以添加参数l3.pop(2)进行删除并返回
25
>>> l3
['Bill']
>>> l3.remove('Bill') # 删除指定元素
>>> l3
[]
>>> l3 = ['Bill', 25, 'Teacher']
>>> l3
['Bill', 25, 'Teacher']
>>> l3.clear()
>>> l3
[]
>>>

利用切片截取列表[n:m]

>>> l2
[100, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
>>> l2[2:6]
[2, 3, 4, 5]
>>> 

列表合并extend

>>> a = [1, 2, 3]
>>> b = [4, 5, 6]
>>> a.extend(b)
>>> a
[1, 2, 3, 4, 5, 6]
>>> 

找出某元素的索引index

>>> l1
['Tommy', 'Maria', 'Andy', 'Julia', [100, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]]
>>> l1.index('Tommy')
0
>>> 

反向列表中元素reverse, [::-1]

>>> l2.reverse()
>>> l2
[10, 9, 8, 7, 6, 5, 4, 3, 2, 20, 1, 100]
>>> l2[::-1]
[100, 1, 20, 2, 3, 4, 5, 6, 7, 8, 9, 10]
>>> 

列表排序sort([func])

>>> list1 = ['Google', 'Runoob', 'Taobao', 'Baidu']
>>> list1.sort()
>>> list1
['Baidu', 'Google', 'Runoob', 'Taobao']

列表复制copy

>>> list3 = [x for x in range(10)]
>>> list1 = list3.copy() # 深拷贝
>>> list1
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> list1[2] = 100 
>>> list3
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> list1
[0, 1, 100, 3, 4, 5, 6, 7, 8, 9]
>>> list2 = list1 # 浅拷贝
>>> list2
[0, 1, 100, 3, 4, 5, 6, 7, 8, 9]
>>> list1[2] = 2
>>> list1
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> list2
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>>

列表长度len，最大值max

>>> l1 = [x for x in range(5)]
>>> len(l1)
5
>>> max(l1)
4
>>>min(l1)
0 

将元组转换为列表list

>>> tup = (1, 2, 3)
(1, 2, 3)
>>> list(tup)
[1, 2, 3]