列表的格式:变量A的类型为列表
namesList = ['xiaoWang','xiaoZhang','xiaoHua']
列表中的元素可以是不同类型的
例如:testlist=[1,‘a']
namesList = ['xiaoWang','xiaoZhang','xiaoHua'] print(namesList[0]) print(namesList[1]) print(namesList[2])
namesList = ['xiaoWang','xiaoZhang','xiaoHua'] for i in namesList: print(i)
namesList = ['xiaoWang','xiaoZhang','xiaoHua'] length=len(namesList) i=0 while i<length: print(namesList[i]) i+=1
通过append()可以向列表尾部添加元素
namesList = ['xiaoWang','xiaoZhang','xiaoHua'] name=['xiaoFei','xiaoLe'] namesList.append(name) print(namesList)
通过extend可以将另一个集合中的元素逐一添加到列表中
namesList = ['xiaoWang','xiaoZhang','xiaoHua'] name=['xiaoFei','xiaoLe'] namesList.extend(name) print(namesList)
insert(index, object) 在指定位置index前插入元素object
namesList = ['xiaoWang','xiaoZhang','xiaoHua'] namesList.insert(1,'6666') print(namesList)
append和extend区别:
append方法用于在列表末尾添加新的对象,它是把添加的对象当成一个整体追加到末尾
extend用于在列表末尾一次性追加另一个序列中的多个值(用新列表扩展原来的列表)
修改元素的时候,要通过下标来确定要修改的是哪个元素,然后才能进行修改
namesList = ['xiaoWang','xiaoZhang','xiaoHua'] namesList[1]='huaHua' print(namesList)
in(存在),如果存在那么结果为true,否则为false
namesList = ['xiaoWang','xiaoZhang','xiaoHua'] name=input('请输入你的名字:') if name in namesList: print('找到了') else: print('没找到')
not in(不存在),如果不存在那么结果为true,否则false
namesList = ['xiaoWang','xiaoZhang','xiaoHua'] name=input('请输入你的名字:') if name not in namesList: print('没找到') else: print('找到了')
查找列表中元素的索引
namesList = ['xiaoWang','xiaoZhang','xiaoHua'] print(namesList.index('xiaoZhang'))
查看列表中元素出现的次数
namesList = ['xiaoWang','xiaoZhang','xiaoHua','xiaoZhang'] print(namesList.count('xiaoZhang'))
del是根据下标进行删除
namesList = ['xiaoWang','xiaoZhang','xiaoHua','xiaoZhang'] del namesList[1] print(namesList)
pop是默认删除最后一个元素,也可以根据索引进行删除
# 默认删除最后一个 namesList = ['xiaoWang','xiaoZhang','xiaoHua','xiaoZhang'] namesList.pop() print(namesList) # 根据索引进行删除 namesList = ['xiaoWang','xiaoZhang','xiaoHua','xiaoZhang'] namesList.pop(2) print(namesList)
remove是根据元素的值进行删除
namesList = ['xiaoWang','xiaoZhang','xiaoHua','xiaoZhang'] namesList.remove('xiaoHua') print(namesList)
排序(sort,reverse)
sort方法是将list按特定顺序重新排列,默认为由小到大,参数reverse=True可改为倒序,由大到小。
reverse方法是将list逆置。
# sort排序 a=[5,1,6,8,2] a.sort() print(a)
# sort排序之后降序 a=[5,1,6,8,2] a.sort(reverse=True) print(a)
# reverse 反转 a=[5,1,6,8,2] a.reverse() print(a)
静态初始化一个空列表list,使用循环向列表中添加 1–10之间的所有整数;向01中创建的列表list中添加一个字符串“XuanGe”删除下标索引为0的元素将下标索引为1的元素改为66输出列表中的第3个元素
li=[]# 01for i in range(1,10): li.append(i)print(li)# 02li.append('XuanGe')print(li)# 03del li[0]print(li)# 04li[1]=66print(li)# 05print(li[2])
list=[23,34,35,31,22,33,55,43,78,34] list1=[] list2=[[[3,21],2],[4],3] # 01 for i in list: if i % 2 ==0: print(i) list1.append(i) list1.sort() print(list1) # 02 list1.extend(list2) print(list1) print(list1[4][0][1])