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')
name='egon' #name=str('egon')print(type(name))优先掌握
msg=' hello '
print(msg)
print(msg.strip())
msg='***hello*********'
msg=msg.strip('*')
print(msg)
print(msg.lstrip('*'))
print(msg.rstrip('*'))
注:strip只能去除最左边以及最右边的空格,去除不了中间的空格
如:L= a a #三个空格夹着2个a
print(L.strip())
输出的结果是a a
用处:我们不能控制用户的输入,为了判断方便,将无用部分剔除
例:剔除用户误输入的空格,以免影响判断
while True:
name=input('user: ').strip()
password=input('password: ').strip()
if name == 'egon' and password == '123':
print('login successfull')
字符串切分后变为列表,列表不能再进行切分
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))#后面的数字代表,切分次数,默认从左往右切分
用处: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]))
msg='hello world'print(msg[1:3]) #1 2print(msg[1:4]) #1 2 3
作用:算出字符串的长度(包括空格)print(len('hell 123'))
作用:找出字符串中某个字符在字符串中的位置name='hell 123'print(name.index('h'))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))
#format
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())
#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())
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')
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'))
=====>part1:数字类型掌握:int,float了解:Long(在python2中才有),complexnum=10num=int(10)print(type(num),num)salary=12.5salary=float(12.5)print(type(salary),salary)进制转换(了解部分)二进制:0 11010101res=1*(2**6)+1*(2**4)+1*(2**2)+1*1print(res)bin(11) #十进制的11转成二进制八进制:0-7print(oct(11))#十进制的11转成八进制十六进制:0-9 a-fprint(hex(11))print(hex(16))复数x=1-2jprint(x.real)print(x.imag)