1、strip
strip 脱去（...的）衣服
去掉左右两边的空白msg=‘ hellprint(msg)
1 1 print(msg.strip()) #去掉左右两边的空白 2 2 3 3 hello 4 4 hello 5 5 6 6 msg=‘********hello************‘ 7 7 print(msg) 8 8 print(msg.strip(‘*‘)) #指定的去掉左右两边的* 9 9 ********hello************ 10 10 11 11 hello 12 12 (1)lstrip 指定去掉左边的* 13 13 # print(msg.lstrip(‘*‘)) 14 14 msg=‘********hello************‘ 15 15 print(msg) 16 16 print(msg.lstrip(‘*‘)) #指定去掉左边的* 17 17 ********hello************ 18 18 hello************ 19 19 20 20 (2)rstrip 指定去掉右边的连续的* 21 21 # print(msg.rstrip(‘*‘)) 22 22 msg=‘********hello************‘ 23 23 print(msg) 24 24 print(msg.rstrip(‘*‘)) #指定去掉右边的连续的* 25 25 ********hello************ 26 26 ********hello
#strip的用处
# while True:
# name=input(‘user: ‘).strip()
# password=input(‘password: ‘).strip()
#
# if name == ‘egon‘ and password == ‘123‘:
# print(‘login successfull‘)
2、split 切分
1 1 info=‘root:x:0:0::/root:/bin/bash‘ 2 2 print(info[0]+info[1]+info[2]+info[3]) 3 3 root 4 5 info=‘root:x:0:0::/root:/bin/bash‘ 6 print(info[0]+info[1]+info[2]+info[3]) 7 8 info=‘root:x:0:0::/root:/bin/bash‘ 9 print(info[0]+info[1]+info[2]+info[3]) 10 info=‘root:x:0:0::/root:/bin/bash‘ 11 print(info[0]+info[1]+info[2]+info[3]) 12 13 user_l=info.split(‘:‘) #用内置方法以‘：’能把字符串类型以列表的形式呈现出来，来取值 14 print(user_l[0]) 15 16 17 # msg=‘hello world egon say hahah‘ 18 # print(msg.split()) #默认以空格作为分隔符 19 msg=‘hello world egon say hahah‘ 20 print(msg.split()) #默认以空格为分隔符 21 [‘hello‘, ‘world‘, ‘egon‘, ‘say‘, ‘hahah‘] 22 23 24 25 26 cmd=‘download|xhp.mov|3000‘ 27 # cmd_l=cmd.split(‘|‘) 28 # print(cmd_l[1]) 29 # print(cmd_l[0]) 30 31 # print(cmd.split(‘|‘,1))
用处
# while True:
# cmd=input(‘>>: ‘).strip()
# if len(cmd) == 0:continue
# cmd_l=cmd.split()
# print(‘命令是:%s 命令的参数是:%s‘ %(cmd_l[0],cmd_l[1]))
3、len 长度
1 1 # print(len(‘hell 123‘)) 2 2 print(len(‘hell 123‘)) #查看字符串的长度 3 8 #字符串长度为8
4、索引
根据索引来取出子字符串
1 msg=‘hello world 2 print(msg[1:3]) #1 2 3 print(msg[1:4]) #1 2 3 4 msg=‘hello world‘ 5 print(msg[1:3]) #切出字符串子集但顾头不顾尾 6 el
5、混合应用
1 oldboy_age=84 2 while True: 3 age=input(‘>>: ‘).strip() 4 if len(age) == 0:continue 5 if age.isdigit(): 6 age=int(age) 7 else: 8 print(‘must be int‘)
6、endswith
1 #startswith,endswith 2 # name=‘alex_SB‘ 3 # print(name.endswith(‘SB‘)) #查找字符串结尾里是否有输入的参数，有着返回True,没有返回False 4 # print(name.startswith(‘alex‘)) #查找开头是否有输入的参数，有着返回True，没有返回False
7、replace
1 #replace 2 # name=‘alex say :i have one tesla,my name is alex‘ 3 # print(name.replace(‘alex‘,‘SB‘,1)) 4 name = ‘alex say :i have one tesla,my name is alex‘ 5 print(name.replace(‘alex‘,‘SB‘,1)) #在开头和结尾添加指定字符 6 SB say :i have one tesla,my name is alex
8、占位符
1 # %s对应所有字符 一一对应后面的元素
2 print(‘my name is %s my age is %s my sex is %s‘ %(‘egon‘,18,‘male‘))
3 #把{}当作一个占位符，.format调用对应每一个后面输入的字符
4 print(‘my name is {} my age is {} my sex is {}‘.format(‘egon‘,18,‘male‘))
5 my name is egon my age is 18 my sex is male
6 #根据{}里的索引来对应值，当{}没有值时默认为一一对应。
7 print(‘my name is {0} my age is {1} my sex is {0}:{2}‘.format(‘egon‘,18,‘male‘))
8 my name is egon my age is 18 my sex is egon:male
9 #根据{}里的输入的key来准确调用key对应的元素
10 print(‘my name is {name} my age is {age} my sex is {sex}‘.format(
11 sex=‘male‘,
12 age=18,
13 name=‘egon‘))
14 my name is egon my age is 18 my sex is male
9、find、index、count查找
1 #可以指定范围查找但顾头不顾尾，找到则返回该值的索引号，没有则返回-1不报错， 2 # find 查找 3 name=‘goee say hello‘ 4 print(name.find(‘e‘,1,3)) 5 #index 查找 6 可以指定范围查找但顾头不顾尾，找到则返回该字符串的索引号，没有则报错 7 name=‘goee say hello‘ 8 print(name.index(‘s‘)) 9 10 #count 11 指定参数，查找字符串里的元素，有则返回这个查找的值里有多少数，有1个就返回1，2个就返回2 等等，没有则返回0 12 name=‘aaaaaaaa aaaaa aaa‘ 13 print(name.count(‘a‘)) 14 16
10、join
1 #join 2 # info=‘root:x:0:0::/root:/bin/bash‘ 3 # print(info.split(‘:‘)) 4 5 # l=[‘root‘, ‘x‘, ‘0‘, ‘0‘, ‘‘, ‘/root‘, ‘/bin/bash‘] 6 # print(‘:‘.join(l)) 7 8 #join 两个物体连接处 9 指定分隔符默认，用:连接起来 10 l=[‘root‘, ‘x‘, ‘0‘, ‘0‘, ‘‘, ‘/root‘, ‘/bin/bash‘] 11 print(‘:‘.join(l)) 12 root:x:0:0::/root:/bin/bash
11、lower,upper大小写转换
1 #lower,upper 2 # name=‘eGon‘ 3 # print(name.lower()) 4 # print(name.upper()) 5 将大写字母全转为小写字母 6 name = ‘Egon‘ 7 print(name.lower()) 8 egon 9 10 将小写字母全转为大写 11 name = ‘Egon‘ 12 print(name.upper())
了解部分
1、expandtabs 指定参数多少个空格符
1 name=‘egon\thello‘ 2 print(name) 3 print(name.expandtabs(3)) 4 egon hello 5 egon hello
2、center,ljust,rjust,zfill
1 以原有的变量的字符为中心两边添加指定数量的符号 2 name=‘egon‘ 3 print(name.center(30,‘_‘)) 4 _____________egon_____________ 5 6 ljust 7 原有元素左对齐后面添加指定数量的符号 8 name=‘egon‘ 9 print(name.ljust(30,‘*‘)) 10 egon************************** 11 rjust 12 原有元素右对齐，往左边添加指定数量的符号 13 name=‘egon‘ 14 print(name.rjust(30,‘*‘))
3、captalize,swapcase,title
1 captalize 2 首字母大写，其余部分小写 3 name=‘eGOn‘ 4 print(name.capitalize()) 5 Egon 6 7 title 8 每个单词的首字母大写 9 msg=‘egon say hi‘ 10 print(msg.title()) 11 12 swapcase 13 小写互相对调大写变小写，小写变大写 14 name=‘eGOn‘ 15 print(name.swapcase()) 16 EgoN
#在python3中
4、元素判断
1 1 isdigit 是否为数字 2 2 判断字符串里是否为数字，是则返回True，不是则返回False 3 3 4 4 num0=‘4‘ 5 5 num1=b‘4‘ #bytes 6 6 num2=u‘4‘ #unicode,python3中无需加u就是unicode 7 7 num3=‘四‘ #中文数字 8 8 num4=‘Ⅳ‘ #罗马数字 9 9 10 10 print(num0.isdigit()) 11 11 print(num1.isdigit()) 12 12 print(num2.isdigit()) 13 13 print(num3.isdigit()) 14 14 print(num4.isdigit()) 15 #isdecimal:str,unicode 16 # num0=‘4‘ 17 # num1=b‘4‘ #bytes 18 # num2=u‘4‘ #unicode,python3中无需加u就是unicode 19 # num3=‘四‘ #中文数字 20 # num4=‘Ⅳ‘ #罗马数字 21 # print(num0.isdecimal()) 22 # # print(num1.) 23 # print(num2.isdecimal()) 24 # print(num3.isdecimal()) 25 # print(num4.isdecimal()) 26 27 isdecimal 28 判断一个数是否为十进制数，是则返回True,不是则返回False 29 num0=‘4‘ 30 num1=b‘4‘ 31 num2=u‘4‘ 32 num3=‘四‘ 33 num4=‘Ⅳ‘ 34 print(num0.isdecimal()) 35 print(type(num1)) 36 print(num2.isdecimal()) 37 print(num3.isdecimal()) 38 print(num4.isdecimal()) 39 True 40 <class ‘bytes‘> 41 True 42 False 43 False 44 45 46 #isnumeric:str,unicode,中文，罗马 47 # num0=‘4‘ 48 # num1=b‘4‘ #bytes 49 # num2=u‘4‘ #unicode,python3中无需加u就是unicode 50 # num3=‘四‘ #中文数字 51 # num4=‘Ⅳ‘ #罗马数字 52 # 53 # print(num0.isnumeric()) 54 # # print(num1) 55 # print(num2.isnumeric()) 56 # print(num3.isnumeric()) 57 # print(num4.isnumeric()) 58 59 isnumeric 同质异构的 60 只针对与unicode字符的判断是否为数字，是则为真不是则为假 61 num0=‘4‘ 62 num1=b‘4‘ 63 num2=u‘4‘ 64 num3=‘四‘ 65 num4=‘Ⅳ‘ 66 print(num0.isnumeric()) 67 print(type(num1)) 68 print(num2.isnumeric()) 69 print(num3.isnumeric()) 70 print(num4.isnumeric()) 71 True 72 <class ‘bytes‘> 73 True 74 True 75 True
5、is其他 isalnum、isalpha
1 # name=‘egon123‘ 2 # print(name.isalnum()) #字符串由字母和数字组成 3 # name=‘asdfasdfa sdf‘ 4 # print(name.isalpha()) #字符串只由字母组成 5 # 6 isalnum 字符测试 7 测试变量里的元素是否为字母和数字组成 8 name = ‘egon123‘ 9 print(name.isalnum()) 10 True
时间： 2024-03-13 02:26:16