字符串及用法

1.%s,%d

举例1：name='egon'

　　　  age=20

　　　  print("my name is %s  my age is %s" %(name,age))#%s既能接受字符串，也能接受数字

　　　  print(‘my name is %s  my age is %d’ %(name,age))#%d只能接受数字

2.字符串方法

# name='egon' #name=str('egon')

# print(type(name))

 

 

#优先掌握

#1.移除空白strip

# msg='             hello         '

# print(msg)

# print(msg.strip())

# 移除‘*’

# msg='***hello*********'

# msg=msg.strip('*')

# print(msg)

#移除左边的

# print(msg.lstrip('*'))

#移除右边的

# print(msg.rstrip('*'))

 

#用处

while True:

    name=input('user: ').strip()

    password=input('password: ').strip()

    if name == 'egon' and password == '123':

        print('login successfull')

 

 

 

#切分split

# info='root:x:0:0::/root:/bin/bash'

# print(info[0]+info[1]+info[2]+info[3])

 

# user_l=info.split(':')

# print(user_l[0])

 

# msg='hello world egon say hahah'

# print(msg.split()) #默认以空格作为分隔符

 

#cmd='download|xhp.mov|3000'

# cmd_l=cmd.split('|')

# print(cmd_l[1])

# print(cmd_l[0])

# 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]))

 

 

 

 

 

#长度len

# print(len('hell 123'))

 

 

#索引

# 切片:切出子字符串

# msg='hello world'

# print(msg[1:3]) #1 2

# print(msg[1:4]) #1 2 3

 

 

 

# 掌握部分

oldboy_age=84

while True:

    age=input('>>: ').strip()

    if len(age) == 0:

        continue

    if age.isdigit():

        age=int(age)

    else:

        print('must be int')

 

 

 

 

 

#startswith,endswith

# name='alex_SB'

# print(name.endswith('SB'))

# print(name.startswith('alex'))

 

 

#replace

# name='alex say :i have one tesla,my name is alex'

# print(name.replace('alex','SB',1))

 

# print('my name is %s my age is %s my sex is %s' %('egon',18,'male'))

# print('my name is {} my age is {} my sex is {}'.format('egon',18,'male'))

# print('my name is {0} my age is {1} my sex is {0}:

{2}'.format('egon',18,'male'))

# print('my name is {name} my age is {age} my sex is {sex}'.format(

#     sex='male',

#     age=18,

#     name='egon'))

 

 

# name='goee say hello'

# # print(name.find('S',1,3)) #顾头不顾尾,找不到则返回-1不会报错,找到了则显示索引

# # print(name.index('S')) #同上,但是找不到会报错

#

# print(name.count('S',1,5)) #顾头不顾尾,如果不指定范围则查找所有

 

 

#join

# info='root:x:0:0::/root:/bin/bash'

# print(info.split(':'))

 

# l=['root', 'x', '0', '0', '', '/root', '/bin/bash']

# print(':'.join(l))

 

 

#lower,upper

# name='eGon'

# print(name.lower())

# print(name.upper())

 

 

#了解部分

#expandtabs

# name='egon hello'

# print(name)

# print(name.expandtabs(1))

 

 

#center,ljust,rjust,zfill

# name='egon'

# # print(name.center(30,'-'))

# print(name.ljust(30,'*'))

# print(name.rjust(30,'*'))

# print(name.zfill(50)) #用0填充

 

 

#captalize,swapcase,title

# name='eGon'

# print(name.capitalize()) #首字母大写,其余部分小写

# print(name.swapcase()) #大小写翻转

# msg='egon say hi'

# print(msg.title()) #每个单词的首字母大写

 

 

#在python3中

num0='4'

num1=b'4' #bytes

num2=u'4' #unicode,python3中无需加u就是unicode

num3='四' #中文数字

num4='Ⅳ' #罗马数字

 

 

#isdigt:str,bytes,unicode

# print(num0.isdigit())

# print(num1.isdigit())

# print(num2.isdigit())

# print(num3.isdigit())

# print(num4.isdigit())

 

#isdecimal:str,unicode

# num0='4'

# num1=b'4' #bytes

# num2=u'4' #unicode,python3中无需加u就是unicode

# num3='四' #中文数字

# num4='Ⅳ' #罗马数字

# print(num0.isdecimal())

# # print(num1.)

# print(num2.isdecimal())

# print(num3.isdecimal())

# print(num4.isdecimal())

 

#isnumeric:str,unicode,中文，罗马

# num0='4'

# num1=b'4' #bytes

# num2=u'4' #unicode,python3中无需加u就是unicode

# num3='四' #中文数字

# num4='Ⅳ' #罗马数字

#

# print(num0.isnumeric())

# # print(num1)

# print(num2.isnumeric())

# print(num3.isnumeric())

# print(num4.isnumeric())

 

 

 

 

#is其他

# name='egon123'

# print(name.isalnum()) #字符串由字母和数字组成

# name='asdfasdfa sdf'

# print(name.isalpha()) #字符串只由字母组成

#

 

# name='asdfor123'

# print(name.isidentifier())

name='egGon'

print(name.islower())

# print(name.isupper())

# print(name.isspace())

name='Egon say'

print(name.istitle())