列表的魔法

以中括号括起来，以","分隔每个元素，列表中的元素可以是数字，字符串，列表中可以嵌套列表。列表的列表中还能嵌套列表，也可以是布尔值。所有的都能放进去。

li = [1,12,9,"age",["hehe",2,"wang",["wanggang","xudong"]],"end"] print(li[4][3][1]) --- xudong ---

切片

li = [1,12,9,"age",["hehe",2,"wang",["wanggang","xudong"]],"end"] print(li[3:-1]) --- ['age', ['hehe', 2, 'wang', ['wanggang', 'xudong']]] # 取大于等于3，小于5 print(li[3:5]) --- ['age', ['hehe', 2, 'wang', ['wanggang', 'xudong']]]

支持for循环，while循环，break,continue

for item in li: print(item) --- 1 12 9 age ['hehe', 2, 'wang', ['wanggang', 'xudong']] end

列表中的元素是可以被修改的，字符串不能被修改

li = [1,12,9,"age",["hehe",2,"wang",["wanggang","xudong"]],"end"] li[1] = 250 print(li) --- [1, 250, 9, 'age', ['hehe', 2, 'wang', ['wanggang', 'xudong']], 'end'] # 切片修改 li[1:3] = [250,500] print(li) --- [1, 250, 500, 'age', ['hehe', 2, 'wang', ['wanggang', 'xudong']], 'end']

可以被删除

del li[1] print(li) --- [1, 9, 'age', ['hehe', 2, 'wang', ['wanggang', 'xudong']], 'end'] # 通过切片删除 li = [1,12,9,"age",["hehe",2,"wang",["wanggang","xudong"]],"end"] del li[4:-1] print(li) --- [1, 12, 9, 'age', 'end']

数字转字符串str()
字符串转数字int()

a = 123 int(a) a = 123 str(a)

字符串转列表

a = "yangyajun" print(list(a)) --- ['y', 'a', 'n', 'g', 'y', 'a', 'j', 'u', 'n']

append追加

def append(self,p_object) li = [11,22,33,44] v = li.append(5) print(v) --- None # 在原来值后追加 print(li) --- [11,22,33,44,5]

清空

li.clear() print(li) --- []

copy复制,浅拷贝

v = li.copy() print(v) --- [11,22,33,44]

计数count,计算元素出现的次数

v = li.count(22) print(v) --- 2

iterable迭代，必须传一个可迭代对象

li = [11,22,33,22,44] li.extend([9898,"不得了"]) print(li) --- [11, 22, 33, 22, 44, 9898, '不得了']

index,根据值找索引（位置）

def index(self,value,start=None, stop=None):... v = li.index(33) print(v) --- 1

insert,根据指定位置（索引位置）插入元素

li = [11,22,33,22,44] v = li.insert(0,99) print(li) --- [99, 11, 22, 33, 22, 44]

pop,默认把最后一个元素删除,并获取被删除的值

def pop(self,index=None) li.pop() print(li,v) --- [11, 22, 33, 22] 44 # 根据索引的位置删除值，并获取,如果没有指定索引，默认是最后一个 v = li.pop(1) print(li,v) --- [11, 33, 22, 44] 22

remove,删除列中中指定值，左边优先

li.remove(22) print(li,v) --- [22, 33, 22, 44] None

将当前列表进行反转

li = [11,22,33,22,44] li.reverse() print(li) --- [44, 22, 33, 22, 11]

排序

li = [11,44,22,33,22] li.sort() print(li) --- [11, 22, 22, 33, 44] # 从大到小排序 li.sort(revers=True) --- [44, 33, 22, 22, 11]