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  • 数字类型

    一,基本使用

    1.int用途:年龄,号码,等级等。。。

    2.定义方式

    age=18  #age=int(18)

    x=int('111')  #int 只能将纯数字的字符串换成十进制的整型。

    print(type(x))

    3,常用操作和内置方法

    算术运算和比较运算

    二:该类型总结:

    1,存一个值还是多个值?

    只能存一个值。

    例如:age=18

    2.有序还是无序?(看是否有索引)

    没有无序这么一说。

    3.可变 还是不可变?

    #可变指的是改变原值,即在原值基础上进行修改

    #可变类型的底层原理:在id不变的情况下,值可以改变

    #int 是不可变数据类型。

    了解(**)

    # 长整型Long,只有在python2中才有长整型号
    # 复数complex
    # x=1-2j
    # print(x.real# print(x.imag)
    # print(type(x))


    字符串类型
    一,基本使用
    1.用途:描述性质的数据,比如人的名字,单个爱好,地址。
    2.定义方式:
    name='egon'
    #name=str('egon')
    # x=str(1)
    # y=str(1.1)
    # z=str([1,2,3])
    # n=str({'a':1})
    # print(type(x))
    # print(type(y))
    # print(type(z))
    # print(type(n))

    3.常用操作+内置方法
    优先掌握的操作(*****)
    1.按照索引取值(正向取+反向取):只能取
    msg='hello world'
    print(type(msg[5]))     #取出的就是字符串类型

    print(msg[-1])    #取出的是d

    2. 切片(骨头不顾尾,步长)
    msg='hello world'

    print(msg[1:5],type(msg[1:5]))    #取出的是 ello ,字符串类型
    print(msg[6:-1]) #取出的是 worl
    print(msg[6:11])    #取出的是world 
    print(msg[6:]) #取出的是world

    print(msg[6::2])     #后面的2代表步长为2,取出的是wrd


    # 了解(**)

    # print(msg[0:])
    # print(msg[::-1])
    # msg='hello world'
    # print(msg[-3:-6:-1])
    # print(msg[6:9:-1])


    3.长度len
    print(len(msg))   #取出的是11

    4.成员运算 in 和 not in
    print('sb'in 'my name is alex' )   #打出的是 False

    print('egon' not in 'my name is alex,alex is sb')    #打出的是True,  推荐使用

    # print(not 'egon' in  'my name is alex,alex is SB')  #打出的是 True

    5.移除空白strip
    name=' e gon '
     print(name.strip())

    print(name.strip())

    # name='****A*e*gon****'
    print(name.strip('*')) #打印出来的是 A*e*gon

    name='****egon****'

    print(name.lstrip('*')) #打出的是 egon**** 去除左边的*

    print(name.rstrip('*'))      #打出的是****egon     移除右边的*


    例如:
    # pwd=input('>>: ').strip() #pwd='123  '
    # if pwd == '123':
    # print('login successful')

    msg='cccabcdefgccccc'
    print(msg.strip('c')) #取出的值是abcdefg 从左向右和从右向左依次找c,碰到不是c的就不移除,

    print('*-=egon *&^'.strip('-= *&^'))    打印出egon


    #6、切分split
    # msg='egon:18:male:180:160'
    # l=msg.split(':')
    # print(l)
    # print(l[3])
    #7、循环
    # msg='hello world'
    # for x in msg:
    # print(x)

    # 需要掌握的操作(****)
    #1、strip,lstrip,rstrip
    #2、lower,upper
    # name='EoN'
    # print(name.lower())

    # name='egonN'
    # print(name.upper())

    #3、startswith,endswith
    # print('alex is SB'.startswith('alex'))
    # print('alex is SB'.endswith('B'))

    #4、format的三种玩法
    # print('my name is %s my age is %s' %('egon',18))
    # print('my name is {name} my age is {age}'.format(age=18,name='egon')) # 可以打破位置的限制,但仍能指名道姓地为指定的参数传值

    # print('my name is {} my age is {}'.format('egon',18))
    # print('my name is {0} my age is {1} {1} {1} {1}'.format('egon',18))

    #5、split,rsplit
    # info='egon:18:male'
    # print(info.split(':',1))

    # print(info.split(':',1)) #['egon','18:male']
    # print(info.rsplit(':',1)) #['egon:18','male']

    #6、join:只能将元素全为字符串的列表拼成一个大的字符串
    # info='egon:18:male'
    # l=info.split(':')
    # print(l)
    # new_info='-'.join(l)
    # print(new_info)

    # num=['a','b','c']
    # ':'.join(num) #'a'+':'+'b'+':'+'c'

    # num=[1,2,'c']
    # ':'.join(num) #1+':'+2+':'+'c'

    #7、replace
    # msg='my name is wupeiqi,wupeiqi is SB'
    # print(msg.replace('wupeiqi','Pig',1))
    # print(msg)

    #8、isdigit
    # print('111.1'.isdigit())
    # print('1111'.isdigit())

    # AGE=73
    # age=input('>>: ').strip() #age='asdfasdf'
    # if age.isdigit():
    # age=int(age)
    # if age > AGE:
    # print('too big')
    # elif age < AGE:
    # print('too small')
    # else:
    # print('you got it')
    # else:
    # print('必须输入数字啊傻叉')

    # 其他操作(了解即可)(**)
    #1、find,rfind,index,rindex,count
    msg='my name is alex,alex is hahaha'
    # print(msg.find('alex'))
    # print(msg.find('SB')) #找不到会返回-1

    # print(msg.index('alex'))
    # print(msg.index('SB')) # 找不到index会报错

    # print(msg.find('alex',0,3))

    # print(msg.count('alex'))
    # print(msg.count('alex',0,15))

    #2、center,ljust,rjust,zfill
    # print('info egon'.center(50,'-'))
    # print('info egon'.ljust(50,'-'))
    # print('info egon'.rjust(50,'-'))
    # print('info egon'.zfill(50))

    #3、expandtabs
    # print('a b c'.expandtabs(1))

    #4、captalize,swapcase,title
    # print('my name is egon'.capitalize())
    # print('my Name Is egon'.swapcase())
    # print('my name is egon'.title())

    #5、is数字系列
    num1=b'4' #bytes
    num2=u'4' #unicode,python3中无需加u就是unicode
    num3='壹' #中文数字
    num4='Ⅳ' #罗马数字

    #isdigit():bytes,unicode
    # print(num1.isdigit())
    # print(num2.isdigit())
    # print(num3.isdigit())
    # print(num4.isdigit())

    #isdecimal():unicode
    # print(num2.isdecimal())
    # print(num3.isdecimal())
    # print(num4.isdecimal())

    #isnumberic;unicode,中文,罗马
    # print(num2.isnumeric())
    # print(num3.isnumeric())
    # print(num4.isnumeric())

    #6、is其他
    # print('abasdf123123'.isalnum())
    # print('asdfasdf'.isalpha())
    # print('egon'.islower())
    # print('ABC'.isupper())

    # print(' '.isspace())
    # print('My Name Is Egon'.istitle())


    # #二:该类型总结
    # 1 存一个值or存多个值
    # 只能存一个值
    #
    # 2 有序or无序
    # 有序

    # 3 可变or不可变
    # 不可变

    name='egon'
    print(id(name))
    name='alex'
    print(id(name))


    列表类型


    #6、切分split
    # msg='egon:18:male:180:160'
    # l=msg.split(':')
    # print(l)
    # print(l[3])
    #7、循环
    # msg='hello world'
    # for x in msg:
    # print(x)

    # 需要掌握的操作(****)
    #1、strip,lstrip,rstrip
    #2、lower,upper
    # name='EoN'
    # print(name.lower())

    # name='egonN'
    # print(name.upper())

    #3、startswith,endswith
    # print('alex is SB'.startswith('alex'))
    # print('alex is SB'.endswith('B'))

    #4、format的三种玩法
    # print('my name is %s my age is %s' %('egon',18))
    # print('my name is {name} my age is {age}'.format(age=18,name='egon')) # 可以打破位置的限制,但仍能指名道姓地为指定的参数传值

    # print('my name is {} my age is {}'.format('egon',18))
    # print('my name is {0} my age is {1} {1} {1} {1}'.format('egon',18))

    #5、split,rsplit
    # info='egon:18:male'
    # print(info.split(':',1))

    # print(info.split(':',1)) #['egon','18:male']
    # print(info.rsplit(':',1)) #['egon:18','male']

    #6、join:只能将元素全为字符串的列表拼成一个大的字符串
    # info='egon:18:male'
    # l=info.split(':')
    # print(l)
    # new_info='-'.join(l)
    # print(new_info)

    # num=['a','b','c']
    # ':'.join(num) #'a'+':'+'b'+':'+'c'

    # num=[1,2,'c']
    # ':'.join(num) #1+':'+2+':'+'c'

    #7、replace
    # msg='my name is wupeiqi,wupeiqi is SB'
    # print(msg.replace('wupeiqi','Pig',1))
    # print(msg)

    #8、isdigit
    # print('111.1'.isdigit())
    # print('1111'.isdigit())

    # AGE=73
    # age=input('>>: ').strip() #age='asdfasdf'
    # if age.isdigit():
    # age=int(age)
    # if age > AGE:
    # print('too big')
    # elif age < AGE:
    # print('too small')
    # else:
    # print('you got it')
    # else:
    # print('必须输入数字啊傻叉')

    # 其他操作(了解即可)(**)
    #1、find,rfind,index,rindex,count
    msg='my name is alex,alex is hahaha'
    # print(msg.find('alex'))
    # print(msg.find('SB')) #找不到会返回-1

    # print(msg.index('alex'))
    # print(msg.index('SB')) # 找不到index会报错

    # print(msg.find('alex',0,3))

    # print(msg.count('alex'))
    # print(msg.count('alex',0,15))

    #2、center,ljust,rjust,zfill
    # print('info egon'.center(50,'-'))
    # print('info egon'.ljust(50,'-'))
    # print('info egon'.rjust(50,'-'))
    # print('info egon'.zfill(50))

    #3、expandtabs
    # print('a b c'.expandtabs(1))

    #4、captalize,swapcase,title
    # print('my name is egon'.capitalize())
    # print('my Name Is egon'.swapcase())
    # print('my name is egon'.title())

    #5、is数字系列
    num1=b'4' #bytes
    num2=u'4' #unicode,python3中无需加u就是unicode
    num3='壹' #中文数字
    num4='Ⅳ' #罗马数字

    #isdigit():bytes,unicode
    # print(num1.isdigit())
    # print(num2.isdigit())
    # print(num3.isdigit())
    # print(num4.isdigit())

    #isdecimal():unicode
    # print(num2.isdecimal())
    # print(num3.isdecimal())
    # print(num4.isdecimal())

    #isnumberic;unicode,中文,罗马
    # print(num2.isnumeric())
    # print(num3.isnumeric())
    # print(num4.isnumeric())

    #6、is其他
    # print('abasdf123123'.isalnum())
    # print('asdfasdf'.isalpha())
    # print('egon'.islower())
    # print('ABC'.isupper())

    # print(' '.isspace())
    # print('My Name Is Egon'.istitle())


    # #二:该类型总结
    # 1 存一个值or存多个值
    # 只能存一个值
    #
    # 2 有序or无序
    # 有序

    # 3 可变or不可变
    # 不可变

    name='egon'
    print(id(name))
    name='alex'
    print(id(name))

    
    











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  • 原文地址:https://www.cnblogs.com/fxc-520520/p/9112484.html
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