• python day03 字符串操作


    #bool  True False

    #int ----> str
    i = 1
    s = str(i)
    #str ---> int
    s = '123'
    i = int(s)

    #int ----->bool 只要是0 ----》False 非0就是True
    i = 3
    b = bool(i)
    print(b)
    #bool----> int
    #True 1
    #False 0

    '''
    ps:
    while True:
    pass
    while 1: 效率高
    pass
    '''

    #str --->bool

    #s = "" -----> False
    #非空字符串都是True
    #s = "0" -----> True

    #字符串的索引与切片

    s = 'ABCDLSESRF'
    #索引
    # s1 = s[0]
    # print(s1)
    # s2 = s[2]
    # print(s2)
    # s3 = s[-1]
    # print(s3)
    # s4 = s[-2]
    # print(s4)
    # #ABCD   切片 :顾头不顾尾
    # s5 = s[0:4]
    # print(s5)
    # s6 = s[0:-1]
    # print(s6)
    # s7 = s[:]
    # s8 = s[0:]
    # print(s7,s8)
    # s9 = s[0:0]
    s = 'ABCDLSESRF'  # s[首:尾:步长]
    # s10 = s[0:5:2]
    # print(s10)
    s11 = s[4:0:-1]
    print(s11)
    s12 = s[3::-1]
    print(s12)
    s13 = s[3::-2]
    print(s13)
    s = 'ABCDLSESRF'
    s14 = s[-1::-1]
    print(s14)
    s15 = s[::-1]
    print(s15)

    #字符串的操作

    #s = 'alexWUsir'
    # s1 = s.capitalize()  #首字母大写
    # print(s1)
    
    # 全大写,全小写
    s2 = s.upper()
    s21 = s.lower()
    # print(s2,s21)
    '''
    s_str= 'acEQ1'
    you_input =input('请输入验证码,不区分大小写')
    if s_str.upper() == you_input.upper():
        print('输入成功')
    else:
        print('请重新输入')
    '''
    #大小写翻转
    # s3 = s.swapcase()
    # print(s3)
    
    # 每个隔开(特殊字符或者数字)的单词首字母大写
    # s = 'alex*egon-wusir'
    # s4 = s.title()
    # print(s4)
    # s = 'fade,crazy*w4rri0r_songsong node_3'
    # s4 = s.title()
    # print(s4)
    
    #居中,空白填充
    # s = 'alexWUsir'
    # s5 = s.center(20,'~')
    # print(s5)
    
    # s = 'alex二哥'
    # #公共方法
    # l = len(s)
    # print(l)
    
    # 判断以什么为开头,结尾endswith
    #s = 'alexWUsir'
    # s7 = s.startswith('alex')
    #s8 = s.startswith('e',2,5)
    # print(s7)
    #print(s8)
    
    # find 通过元素找索引,找不到返回-1
    # index通过元素找索引,找不到报错
    # s = 'alexWUsir'
    # s8 = s.find('A')
    # s81 = s.index('A')
    # print(s81,type(s8))
    
    
    #strip rstrip lstrip
    #strip 前后一起删
    # strip 默认删除前后空格
    # s = 'alexWUsir%'
    # s9 = s.strip('%')
    # print(s9)
    # s = ' *a%lexWUsi* r%'
    # s91 = s.strip(' %*')
    # print(s91)
    
    #统计个数,没有返回0
    # s = 'alexaa wusir1'
    # # s11 = s.count('al')
    # # print(s11)
    
    #字符串转化为列表
    # s = ';alex;wusir;taibai'
    # s12 = s.split(';')
    # print(s12)
    
    #format的三种玩法 格式化输出
    # s = '我叫{},今年{},爱好{},再说一下我叫{}'.format('太白',36,'girl','太白')
    # print(s)
    # name = input('请输入名字:')
    # s = '我叫{0},今年{1},爱好{2},再说一下我叫{0}'.format(name,36,'girl')
    # print(s)
    # name = input('请输入名字:')
    # s = '我叫{name},今年{age},爱好{hobby},再说一下我叫{name}'.format(age=18,name=name,hobby='girl')
    # print(s)
    
    #替换
    # s = '来看待街坊邻居复合大师街坊法好的撒见客户'
    # s11 = s.replace('街坊','老王',1)
    # print(s11)

    #####is系列
    name='jinxin123'
    print(name.isalnum()) #字符串由字母或数字组成
    print(name.isalpha()) #字符串只由字母组成
    print(name.isdigit()) #字符串只由数字组成

    #如:content = input(‘请输入内容:’) # 如用户输入:5+9或5+ 9或5 + 9,然后进行分割再进行计算。
    # content=input('>>>').strip()
    # con1=content.split('+')
    # num=0
    # for i in con1:
    #     num+=int(i)
    # print(num)
    第二种方法:
    # content=input('>>>').strip()
    # index = content.find("+")
    # a = int(content[0:index])
    # b = int(content[index+1:])
    # print(a + b)
    #咱们任意输入一串文字+数字 统计出来数字的个数
    s = input("请输入:")  # '1234324324fdsaf1fdsaf12'
    count = 0
    for i in s:
        if i.isdigit():
            count += 1
    print(count)
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  • 原文地址:https://www.cnblogs.com/liujinlei/p/9837397.html
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