python基础2，,1.列表元组列表是我

1.列表元组

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 # yu2 3 names=["啦啦","嘿嘿",‘鱼鱼‘]

我们通过列表下标进行数据的提取:

1 # yu2 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 # yu2 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-15 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

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追加:

1 # yu2 names=["lala","heihei",‘yuyu‘,‘hehe‘,‘haha‘]3 names.append("嘻嘻")4 print(names)5 #结果[‘lala‘, ‘heihei‘, ‘yuyu‘, ‘hehe‘, ‘haha‘, ‘嘻嘻‘]

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插入:

1 # yu2 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‘]

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修改:

1 # yu2 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‘]

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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)

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扩展:

1 # yu2 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]

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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‘]

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统计:

1 # yu2 names=["lala","heihei",‘yuyu‘,‘hehe‘,‘haha‘,‘haha‘]3 print(names.count(‘haha‘))#结果2

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排序:

1 # yu2 names=["1lala","3heihei",‘5yuyu‘,‘4hehe‘,‘2haha‘,‘1haha‘]3 names.sort()4 print(names)

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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‘]

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获取下标:

1 # yu2 names=["0lala","1heihei",‘2yuyu‘,‘3hehe‘,‘4haha‘,‘5haha‘]3 print(names.index("2yuyu"))#2

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元组

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.

2.字符串操作

特性;不可修改.

# yuname=‘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_map10 cata = "my name is {name}, and age is {age}"11 print(cata.format_map({‘name‘:‘young‘,‘age‘:23}))

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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.isupperprint("|".join([‘lala‘,‘hihi‘,‘wow‘]))

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#maketransintab = "aeiou"  #This is the string having actual characters.outtab = "12345" #This is the string having corresponding mapping charactertrantab = str.maketrans(intab, outtab)print(trantab)str = "this is string example....wow!!!"print(str.translate(trantab))#     ‘th3s 3s str3ng 2x1mpl2....w4w!!!‘

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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

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python基础2