day3
#字符串的索引和切片 a ="disDisdj" a1 = a.capitalize()#首字母大写 print(a1) a2 = a.upper()#全大写 a3 = a2.lower()#全小写 print(a2 , a3) a="hsjakjHSH" b=input("请输入验证码:")#不区分大小写 if a.upper() == b.upper(): print("输入成功") #大小写反转 a4=a.swapcase() print(a4) a="shajsh jhadasdh dhjsadh"#中间可以用特殊字符或者数字隔开 a12=a.title() print(a12) #居中.空白填充 a = "dhsakhdkd" a6 = a.center(20,"@") print(a6) #空格补足前八位八位 s="hda/tdakj" s1=s.expandtabs() print(s1) 计算字符长度 s=" dbjkas kjalal"#前后中间的空格也算字数 l=len(s) print(l) 判断是否以“~”为开头或结尾 s = "ssdhkasdlk" # s1=s. startswith("ssdh") # s2=s.startswith("d",2 ,6) s3=s.endswith("k") print(s3) print(s1 , s2) 通过元素找索引,找不到返回-1 s="ssdhkasdlk" s1=s.find("d")#找到并定位 s2=s.find("x")#找不到输出-1 s3=s.index("z")#找不到系统会报错 print(s3) print(s1,s2) 从前后或前后同时同时删除空格和符号strip rstrip lstrip s=" %hsdadadkd& " s1=s.strip(" %&") print(s1) 数有几个字母count s = " %hsdadadkd& " s1=s.count("d")#没有输出0 print(s1) 分割split s = "%hsd adad kd&" s1=s.split()#以空格分割 s2=s.split("d")#以d分割#被分割元素消失 print(s1,s2) 格式化输出 format三种形式 s="我叫{},mu name is {},my name is {}".format("shkshk","jsahs","akhdka") print(s) s1="my name is {0},his name is {1},her name is {2},again my name is {0}".format("gshaaj","dadd","sdada") print(s1) s3="i am {name}, i am {age}, i like {hobby},again i am {name}".format(name ="sassas",age="12",hobby="bassketable") print(s3) 替换replace s="jdshasjdalkjdlad;sdasd'd['aps[" s1=s.replace("s","r",3)#替换三次replace(old. new, 次数) s2=s.replace("s","r")#默认全部替换 print(s1 ,s2) ***is 判断是什么 print(name.isalnum())#由字母和数字组成 print(name.isalpha())#由字母组成 print(name.isdigit())#由数字组成 for循环 循环内部所有元素 s="hsadgakjdhldaiskdsjdsai" for i in s: print(i) in/not in 的用法 s="hsadgakjdhldaiskdsjdsai" if "gaka" not in s: print("重新输入") if "gak" in s: print("重新输入") #数据 #分类 int 12344计算 bool: true or false str: "张三""看来""saskajsha""saksak1728192" list:[1,2,3,4,"泰泰","23456"[0,0,7,8,8]] 元组:只读 dict:字典{"name":"张三","age"="12"} 字典{"name":[1,2,,4,5,],"age":[12,45,45,45,22]}关系型极强 集合{1,3,5,6,"jaksha"} #int操作方法 #int操作方法 #int操作方法 #测数字转换成二进制最小位数bit_length i=2 print(i.bit_length())#转换成二进制的最小位数 #bool值 true false #str---int #此处str只能为数字 #int---str #都行 #int--bool i=3 b=bool(i) #0为false,非0为true print(b) #bool---int #true为1 ,false为0 while 1: = whlie true: #str---bool #""(空字符串)为false,非空字符串就为true s if s: print("jslajks") else: print("hsjkahsjk") 字符串的的索引和切片 字符串的的索引和切片 s="AAKJADL;AJDLSAJ;LFIHDFDND" #索引 s1=s[0] s2=s[3] s3=s[-2]#取倒数第二位 print(s1,s2) #切片 #顾头不顾尾 #s="AAKJADL;AJDLSAJ;LFIHDFDND" s3=s[1:3]#取第二个到第三个[首+1:尾] print(s3) s4=s[0:-3]#第一个取到倒数第四个[首+1:尾-1] print(s4) s5=s[0:] print(s5) s6=s[0:0]#空 print(s6) s7=s[0:6:3]#正着取[首+1:尾:步长-1] print(s7) s8=s[-1:-4:-1]#[首:尾+1:步长] print(s8) s9=s[4:0:-1] print(s9) s10=s[4::-1] print(s10) s11=s[::-1] print(s11) s12=s[-4:-1:1] print(s12)