python3之字符串常用操作练习补充二

  1 #coding:utf-8
  2 
  3 #***将"\t"转为空白符，默认使各段字符串长度为8的整数倍，指定长度则以指定的长度为准
  4 str1 = "\tThis\tis Tab test\t!"
  5 print(str1.expandtabs())
  6 ‘‘‘
  7 输出结果为：
  8          This    is Tab test     !
  9 |8字符   |8字符   |16字符         |!
 10 ‘‘‘
 11 print(16*"*")
 12 
 13 
 14 #***查找字符串出现的位置
 15 #find和index的区别为查找不到内容时index直接抛异常报错，find返回-1
 16 #print(str2.index("lee"))
 17 str2 = "This is find test,do you not how to use find?"
 18 start1 = 0
 19 while True:
 20     index1 = str2.find("find",start1+len("find"),len(str2)-1)
 21     if index1 != -1:
 22         print(index1)
 23         start1 = index1
 24     else:
 25         print("查找结束")
 26         break
 27 
 28 #***字符串的格式化拼接
 29 str3 = "My name is {0},I‘m {1}"
 30 str4 = str3.format("Lee",30)
 31 print(str4)
 32 #两种拼接方法都是可以的，都比“+”的字符串拼接好
 33 str5 = "Are you %s?"
 34 str6 = str5 %("LiNing")
 35 print(str6)
 36 #这种方法让我想起了JSP
 37 str7 = "His name is {name},he is {age}."
 38 str8 = str7.format(name = "Daming",age = 28)
 39 #和上面的类似，直接做成字典传入
 40 str9 = str7.format_map({"name":"Jesson","age":18})
 41 print(str8)
 42 print(str9)
 43 
 44 print(16*"*")
 45 #***字符串的各种判断
 46 #是否为数字或字母，isalnum
 47 print("aA".isalnum())   #True
 48 print("5".isalnum())    #True
 49 print("$".isalnum())    #False
 50 print("Ⅴ".isalnum())    #True
 51 #是否是数字0-9，isdigit
 52 print()
 53 print("aA".isdigit())   #False
 54 print("5".isdigit())    #True
 55 print("#".isdigit())    #False
 56 print("Ⅵ".isdigit())    #False
 57 #是否是数字isnumerice
 58 print()
 59 print("aA".isnumeric()) #False
 60 print("5".isnumeric())  #True
 61 print("^".isnumeric())  #False
 62 print("Ⅵ".isnumeric())  #True
 63 #是否为字母isalpha,a~z和A~Z为True
 64 print()
 65 print("a!dC".isalpha()) #False
 66 print("AS".isalpha())
 67 #是否是十进制小数isdecimal
 68 
 69 #是否为小写islower
 70 
 71 #是否为大写isupper
 72 
 73 #是否为空格isspace
 74 print()
 75 print("\t".isspace())   #True
 76 print(" ".isspace())    #True
 77 
 78 #是否为标题istitle
 79 
 80 print(16*"*")
 81 
 82 #***分隔符的操作
 83 list1 = ["E","x","c","e","p","t","i","o","n"]
 84 print("".join(list1))       #Exception
 85 print("-".join(list1))      #E-x-c-e-p-t-i-o-n
 86 
 87 print(16*"*")
 88 #***左右填充
 89 print("253".ljust(12,"$"))
 90 print("253".rjust(12,"$"))
 91 list2 = ["251","5","35","4567"]
 92 #数据靠右对齐
 93 for val in list2:
 94     print(val.rjust(6," "))
 95 
 96 print(16*"*")
 97 #***只去除左边/右边的空格
 98 #lstrip()/rstrip()
 99 
100 #字符串的对应表
101 intab = "abcde"
102 outab = "12345"
103 #将abcde对照为12345
104 trantab = str.maketrans(intab,outab)
105 str10 = "adagsdjfglamxcvb"
106 #利用对照表trantab对str10进行字符替换
107 str11 = str10.translate(trantab)
108 print(str11)        #141gs4jfgl1mx3v2
109 
110 print(8*"*")
111 #***字符串的分割
112 print()
113 str12 = "My name is Lee"
114 print(str12.partition("is"))
115 #print(str12.rpartition("is"))
116 
117 #字符串的替换，转换个数2可选
118 print(str12.replace("e","8",2))
119 
120 print(16*"*")
121 print()
122 #888根据行进行分割，注意，第一行前面有一个回车符，也算一行，相当于lines.split("\n")
123 lines = ‘‘‘
124 This is first line.
125 This is second line.
126 This is third line.
127 ‘‘‘
128 print(lines.splitlines())
129 #输出结果：[‘‘, ‘This is first line.‘, ‘This is second line.‘, ‘This is third line‘]
130 
131 print(16*"*")
132 print()
133 #大小写转换
134 print("aBcD".swapcase())       #AbCd
135 
136 #转为标题，所有单词首字母大写
137 print("This is a title".title())    #This Is A Title