Python-數據類型之列表
阿新 • • 發佈:2019-02-09
let 就是 append wan 反轉 == spa 3.6 6.2
三:列表
3.1 列表的定義語法
中括號,已逗號為分割,可以方任意得數據類型,甚至是對象
li = [‘wangys‘,‘lala‘,123,[1,2,3],{‘name‘:‘wangys‘}]
3.2 取單個元素,取出的是原數據類型
li = [‘wangys‘,‘lala‘,123,[1,2,3],{‘name‘:‘wangys‘}]
l1=li[0]
print(l1,type(l1))
l2=li[2]
print(l2,type(l2))
l3=li[3]
print(l3,type(l3))
3.3 取多個元素,取出的是列表類型
li = [‘wangys‘,‘lala‘,123,[1,2,3],{‘name‘:‘wangys‘}]
l4=li[0:2]
print(l4,type(l4))
3.4 增加元素
增加元素有三種操作
3.4.1 append 在末尾增加
li = [‘wangys‘,‘gongzhu‘]
li.append(‘caomei‘)
li.append(‘1‘)
print(li)
# 需求: 員工列表,往員工列表裏添加員工,可以持續添加,當輸入q時退出
people = [‘wangys‘,‘huisz‘]
flag = True
while flag:
add_people = input("請輸入員工姓名:").strip()
if add_people.upper() == ‘Q‘:
flag = False
else:
people.append(add_people)
print(people)
3.4.2 insert 按照索引進行插入
name = [‘wangys‘,‘chaoyf‘]
name.insert(1,‘huisz‘)
print(name)
3.4.3 extend 將可叠代對象插入到列表的末尾,插入的是可叠代對象的每個元素
整型是不可叠代對象
name = [‘wangys‘,‘chaoyf‘]
name.extend(‘lala‘)
print(name)
name.extend([1,2,3])
print(name)
3.5 刪除元素
3.5.1 pop
1: pop 有返回值,該返回值是被刪除的數據
2:按索引刪除
3:不指定索引,把最後一個元素刪除
name = [‘wangys‘,‘lala‘]
delete_name = name.pop()
print(delete_name,name)
name = ["wangys","haha"]
name.pop(0)
print(name)
name = ["wangys","hehe"]
print(name.pop())
3.5.2 按照元素去刪除
name = [‘wangys‘,‘dede‘]
name.remove(‘dede‘)
print(name)
3.5.3 清空列表
name = ["wangys","dsad"]
name.clear()
print(name)
3.5.4 刪除列表
name = [‘wangys‘]
del name
print(name)
3.5.5 切片刪除
name = [‘wangys‘,"lala",‘haha‘]
del name[1:]
print(name)
3.6 改元素
3.6.1 單個元素改
是按照索引修改,插入什麽就是什麽,單個元素插入
name = ["wangys","haha"]
name[1] = ‘xiaogongzhu‘
print(name)
name = ["wangys","sdfsdf"]
name[1] = [‘xiaogongzhu‘,‘chaomei‘]
print(name)
3.6.2 切片的方式插入
1:首先把切片元素刪除
2:將添加元素以叠代方式插入
name = ["wangys","lala"]
name[1:] = ‘haha‘
print(name)
name = ["wangys","lala"]
name[1:] = ["xiaogongzhu","chaomei"]
print(name)
3.7 元素查找
3.7.1 查看所有元素
name = [‘wangys‘,‘xiaogongzhu‘]
for i in name:
print(i)
3.7.2 查看前兩個元素
查出來的是一個列表
name = [‘wangys‘,‘xiaogongzhu‘]
print(name[:2])
3.8 :列表的一些公共方法
3.8.1 查看列表的長度
wangys_info = ["wangys",23,‘male‘]
l = len(wangys_info)
print(l)
3.8.2 查看列表中某元素的個數
num = [1,2,3,1,2,4]
CountOf1=num.count(1)
print(CountOf1)
3.8.3 根據元素看索引
如果元素不存在報錯
wangys_info = ["wangys",23,‘male‘]
print(wangys_info.index(‘male‘))
print(wangys_info.index(‘malea‘))
3.8.4 排序
正向排序
num = [3,6,2,5,4]
num.sort()
print(num)
反向排序
num = [3,6,2,5,4]
num.sort(reverse=True)
print(num)
3.8.5 列表反轉
num = [3,6,2,5,4]
num.reverse()
print(num)
3.9 :列表的嵌套
wangys_info = [‘wangys‘,23,‘male‘,[‘sing‘,‘play‘,22],25]
取出wangys裏的a
wangys_info = [‘wangys‘,23,‘male‘,[‘sing‘,‘play‘,22],25]
print(wangys_info[0][1])
將列表的第一個元素大寫並替換之前的元素
wangys_info = [‘wangys‘,23,‘male‘,[‘sing‘,‘play‘,22],25]
wangys_info[0] = wangys_info[0].capitalize()
print(wangys_info)
將王誠替換為王永勝
wangys_info = [‘wangys‘,23,‘王誠‘,[‘sing‘,‘play‘,22],25]
wangys_info[2] = wangys_info[2].replace(‘誠‘,‘永勝‘)
print(wangys_info)
wangys_info = [‘wangys‘,23,‘王誠‘,[‘sing‘,‘play‘,22],25]
wangys_info[3][1] = wangys_info[3][1].upper()
print(wangys_info)
Python-數據類型之列表