python3之字符串常用操作练习补充二

字符串常用操作练习补充二

#coding:utf-8

#***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
str1 = "\tThis\tis Tab test\t!"
print(str1.expandtabs())
'''
输出结果为：
         This    is Tab test     !
|8字符   |8字符   |16字符         |!
'''
print(16*"*")


#***查找字符串出现的位置
#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
#print(str2.index("lee"))
str2 = "This is find test,do you not how to use find?"
start1 = 0
while True:
    index1 = str2.find("find",start1+len("find"),len(str2)-1)
    if index1 != -1:
        print(index1)
        start1 = index1
    else:
        print("查找结束")
        break

#***字符串的格式化拼接
str3 = "My name is {0},I'm {1}"
str4 = str3.format("Lee",30)
print(str4)
#两种拼接方法都是可以的，都比“+”的字符串拼接好
str5 = "Are you %s?"
str6 = str5 %("LiNing")
print(str6)
#这种方法让我想起了JSP
str7 = "His name is {name},he is {age}."
str8 = str7.format(name = "Daming",age = 28)
#和上面的类似，直接做成字典传入
str9 = str7.format_map({"name":"Jesson","age":18})
print(str8)
print(str9)

print(16*"*")
#***字符串的各种判断
#是否为数字或字母，isalnum
print("aA".isalnum())   #True
print("5".isalnum())    #True
print("$".isalnum())    #False
print("Ⅴ".isalnum())    #True
#是否是数字0-9，isdigit
print()
print("aA".isdigit())   #False
print("5".isdigit())    #True
print("#".isdigit())    #False
print("Ⅵ".isdigit())    #False
#是否是数字isnumerice
print()
print("aA".isnumeric()) #False
print("5".isnumeric())  #True
print("^".isnumeric())  #False
print("Ⅵ".isnumeric())  #True
#是否为字母isalpha,a~z和A~Z为True
print()
print("a!dC".isalpha()) #False
print("AS".isalpha())
#是否是十进制小数isdecimal

#是否为小写islower

#是否为大写isupper

#是否为空格isspace
print()
print("\t".isspace())   #True
print(" ".isspace())    #True

#是否为标题istitle

print(16*"*")

#***分隔符的操作
list1 = ["E","x","c","e","p","t","i","o","n"]
print("".join(list1))       #Exception
print("-".join(list1))      #E-x-c-e-p-t-i-o-n

print(16*"*")
#***左右填充
print("253".ljust(12,"$"))
print("253".rjust(12,"$"))
list2 = ["251","5","35","4567"]
#数据靠右对齐
for val in list2:
    print(val.rjust(6," "))

print(16*"*")
#***只去除左边/右边的空格
#lstrip()/rstrip()

#字符串的对应表
intab = "abcde"
outab = "12345"
#将abcde对照为12345
trantab = str.maketrans(intab,outab)
str10 = "adagsdjfglamxcvb"
#利用对照表trantab对str10进行字符替换
str11 = str10.translate(trantab)
print(str11)        #141gs4jfgl1mx3v2

print(8*"*")
#***字符串的分割
print()
str12 = "My name is Lee"
print(str12.partition("is"))
#print(str12.rpartition("is"))

#字符串的替换，转换个数2可选
print(str12.replace("e","8",2))

print(16*"*")
print()
#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")
lines = '''
This is first line.
This is second line.
This is third line.
'''
print(lines.splitlines())
#输出结果：['', 'This is first line.', 'This is second line.', 'This is third line']

print(16*"*")
print()
#大小写转换
print("aBcD".swapcase())       #AbCd

#转为标题，所有单词首字母大写
print("This is a title".title())    #This Is A Title