python 字符串方法 while补充

字符串内置方法：

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

#优先掌握
#　　　　移除空白strip
# msg=' hello '
# print(msg)
# print(msg.strip())

# msg='***hello*********'
# msg=msg.strip('*')
# print(msg)

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

 

while应用举例：
while True:
name=input('please input your name: ')
password=input('please input your password: ')

if name == 'egon' and password == '123':
print('login successfull')
while True:
cmd=input('>>: ')
if cmd == 'quit':
break
print('====>',cmd)
break

tag=True
while tag:
name=input('please input your name: ')
password=input('please input your password: ')

if name == 'egon' and password == '123':
print('login successfull')
while tag:
cmd=input('>>: ')
# if cmd == 'quit':
# tag=False
# continue
# print('====>',cmd)

if cmd == 'quit':
tag=False
else:
print('====>',cmd)

 

count=0
while count < 10:
if count == 3:
count+=1
continue
print(count)

count+=1
else: #最后执行
print('在最后执行，并且只有在while循环没有被break打断的情况下才执行')


#字符串部分
#一：移除空白
while True:
name=input('user: ').strip()
password=input('password: ').strip()

if name == 'egon' and password == '123':
print('login successfull')

#二：从字符串中切出用户命令的详细信息
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]))

#三：判断用户输入的是否为整型数字，如果是，则转换成整型
oldboy_age=84
while True:
age=input('>>: ').strip()
if len(age) == 0:continue
if age.isdigit():
age=int(age)
else:
print('must be int')

#四：字符串格式化方法
print('my name is {name} my age is {age} my sex is {sex}'.format(
sex='male',
age=18,
name='egon'))