标签：pytho print 元组 嘻嘻 字母 clear center 只读 变量
列表是我们最以后最常用的数据类型之一，通过列表可以对数据实现最方便的存储、修改等操作.
定义列表:
1 # yu 2 3 names=["啦啦","嘿嘿",‘鱼鱼‘]
我们通过列表下标进行数据的提取:
1 # yu 2 names=["啦啦","嘿嘿",‘鱼鱼‘] 3 print(names) 4 print(names[0])#第一个数据从0开始 5 print(names[-1])#倒过来取值
切片:
1 # yu 2 names=["lala","heihei",‘yuyu‘,‘hehe‘,‘haha‘] 3 print(names[1:3])#取下标1 ,不包含下标3 [‘heihei‘, ‘yuyu‘] 4 print(names[1:-1])#取下标1至-1的值，不包括-1 5 print(names[:3])#如果是从头开始取，0可以忽略 6 print(names[3:])#取到最后一个值 7 print(names[3:-1])#取不到最后一个值 8 print(names[0::2])#后面的2是代表，每隔一个元素，就取一个
追加:
1 # yu 2 names=["lala","heihei",‘yuyu‘,‘hehe‘,‘haha‘] 3 names.append("嘻嘻") 4 print(names) 5 #结果[‘lala‘, ‘heihei‘, ‘yuyu‘, ‘hehe‘, ‘haha‘, ‘嘻嘻‘]
插入:
1 # yu 2 names=["lala","heihei",‘yuyu‘,‘hehe‘,‘haha‘] 3 names.insert(2,‘从2插入‘) 4 print(names) 5 #结果[‘lala‘, ‘heihei‘, ‘从2插入‘, ‘yuyu‘, ‘hehe‘, ‘haha‘]
修改:
1 # yu 2 names=["lala","heihei",‘yuyu‘,‘hehe‘,‘haha‘] 3 names[1]=‘修改下标为1‘ 4 print(names) 5 #结果[‘lala‘, ‘修改下标为1‘, ‘从2插入‘, ‘yuyu‘, ‘hehe‘, ‘haha‘]
删除:
1 names=["lala","heihei",‘yuyu‘,‘hehe‘,‘haha‘] 2 #names.clear()#清空列表 3 print(names)#返回[] 4 #del names[1]#删除指定下标的值 5 print(names)#[‘lala‘, ‘yuyu‘, ‘hehe‘, ‘haha‘ 6 #names.remove("yuyu")#删除指定的值 7 print(names) 8 names.pop()#默认删最后一个,也可以加入你祥删除的下标 9 print(names)
扩展:
1 # yu 2 names=["lala","heihei",‘yuyu‘,‘hehe‘,‘haha‘] 3 b=[1,2,3] 4 names.extend(b) 5 print(names)#[‘lala‘, ‘heihei‘, ‘yuyu‘, ‘hehe‘, ‘haha‘, 1, 2, 3]
拷贝(浅拷贝与深拷贝的区别):
1 names=["Young","Jon",["Tom","Jerry"],‘Jems‘,‘Sunny‘] 2 names2 = names.copy() 3 names[1]="浅copy" 4 names[2][0]="深copy" 5 print(‘name1:‘,names) 6 print(‘name2:‘,names2) 7 #结果 8 #name1: [‘Young‘, ‘浅copy‘, [‘深copy‘, ‘Jerry‘], ‘Jems‘, ‘Sunny‘] 9 #name2: [‘Young‘, ‘Jon‘, [‘深copy‘, ‘Jerry‘], ‘Jems‘, ‘Sunny‘]
统计:
1 # yu 2 names=["lala","heihei",‘yuyu‘,‘hehe‘,‘haha‘,‘haha‘] 3 print(names.count(‘haha‘))#结果2
排序:
1 # yu 2 names=["1lala","3heihei",‘5yuyu‘,‘4hehe‘,‘2haha‘,‘1haha‘] 3 names.sort() 4 print(names)
反转:
1 names=["1lala","2heihei",‘3yuyu‘,‘4hehe‘,‘5haha‘,‘6haha‘] 2 names.reverse() 3 print(names) 4 #结果[‘6haha‘, ‘5haha‘, ‘4hehe‘, ‘3yuyu‘, ‘2heihei‘, ‘1lala‘]
获取下标:
1 # yu 2 names=["0lala","1heihei",‘2yuyu‘,‘3hehe‘,‘4haha‘,‘5haha‘] 3 print(names.index("2yuyu"))#2
元组其实跟列表差不多，也是存一组数，只不是它一旦创建，便不能再修改，所以又叫只读列表
定义:
names=("lala","heihei",‘yuyu‘,‘hehe‘,‘haha‘,‘haha‘)
它只有2个方法，一个是count,一个是index.
特性;不可修改.
# yu name=‘young‘ #首字母大写 print(name.capitalize() ) # name.casefold() 大写全部变小写 print(name.center(50,"-") ) #输出----------------------young----------------------- # name.count(‘lex‘) 统计 lex出现次数 # name.encode() 将字符串编码成bytes格式 # name.endswith("g") 判断字符串是否以g结尾 # "Young\tY".expandtabs(10) 输出‘Young Y‘， 将\t转换成多长的空格 print(name.find(‘o‘)) #查找A,找到返回其索引， 找不到返回-1
1 #format 2 cata = "my name is {}, and age is {}" 3 print(cata.format("young",23))#结果my name is young, and age is 23 4 cata = "my name is {}, and age is {}" 5 print(cata.format("23",‘young‘))#my name is 23, and age is young 6 cata = "my name is {name}, and age is {age}" 7 print(cata.format(age=23,name=‘young‘)) 8 9 #format_map 10 cata = "my name is {name}, and age is {age}" 11 print(cata.format_map({‘name‘:‘young‘,‘age‘:23}))
cata = "my name is {name}, and age is {age}" print(cata.index(‘a‘)) print(‘9aA‘.isalnum() ) print(‘9‘.isdigit() )#是否整数) name=‘Hello‘ print(name.isnumeric ) # name.isprintable # name.isspace # name.istitle # name.isupper print("|".join([‘lala‘,‘hihi‘,‘wow‘]))
#maketrans intab = "aeiou" #This is the string having actual characters. outtab = "12345" #This is the string having corresponding mapping character trantab = str.maketrans(intab, outtab) print(trantab) str = "this is string example....wow!!!" print(str.translate(trantab)) # ‘th3s 3s str3ng 2x1mpl2....w4w!!!‘
1 print(cata.partition(‘is‘))#(‘my name ‘, ‘is‘, ‘ {name}, and age is {age}‘) 2 print(cata.swapcase())#大小写互换 3 print(cata.zfill(40)) 4 n=‘hello world‘ 5 print(n.ljust(40, "-")) 6 print(n.rjust(40, "-")) 7 b="ddefdsdff_哈哈" 8 b.isidentifier() #检测一段字符串可否被当作标志符，即是否符合变量命名规则
标签：pytho print 元组 嘻嘻 字母 clear center 只读 变量
原文地址：https://www.cnblogs.com/Young111/p/9279591.html
