python字符串(str)

# value = "raitOrEi"
# v = value.capitalize()#首字母大写
# print(v)
# v1 = v.casefold()#全部变小写，不只是英文的，其他语言特殊的大小写也变换
# print(v1)
# v2 = v.lower()#只是英文变小写
# print(v2)

# 设置宽度，并将内容居中
# 20 代指总长度
# 只能填充一个字符,字符可有可无，没有字符用空格填充
# value = "raitorei"
# v = value.center(20)
# print(v)
# v1 = value.center(20,"*")
# print(v1)
# v2 = value.ljust(20,"*")
# print(v2)
# v3 = value.rjust(20,"*")
# print(v3)
# v4 = value.zfill(20)#只能用0填充
# print(v4)

# 去字符串中寻找，寻找子序列的出现次数
# value = "reraitorei"
# v1 = value.count('re')
# v2 = value.count('re',5)
# v3 = value.count('re',5,6)#起止位置
# print(v1)
# print(v2)
# print(v3)

# encode
# decode

# 以什么开始
# 以什么结尾
# test = "raitorei"
# v = test.startswith('r')
# print(v)
# v = test.endswith('i')
# print(v)

#把字符串中的 tab 符号('\t')转为空格，tab 符号('\t')默认的空格数是 8.
#具体规则是，括号里是多少，以这个数字为一组，如果是开头，空格占位数字多少。比如
# test = "123\t456789"
# v = test.expandtabs()#123     456789  8个一组，空格补缺少的位置
# print(v)
# v1 = test.expandtabs(6)#123   456789  6个一组，空格补缺少的位置
# print(v1)

# 从开始往后找，找到第一个之后，获取位置
# 大于等于开始，小于结束，未找到 -1
# test = "rei"
# v = test.find('r',0,2 )
# print(v)

# index找不到，报错   忽略
# test = "rei"
# v = test.index('a')
# print(v)

# 将一个字符串中的占位符替换为指定的值
# test = "I'm {name}, age {a}"
# print(test)
# v = test.format(name='raitorei',a=22)
# print(v)

#将一个字符串中的占位符替换为指定的值,字典
# test = "I'm {name}, age {a}"
# print(test)
# v = test.format_map({"name": 'raitorei', "a": 22})
# print(v)

# 星号 字符串中是否只包含字母，数字，汉字
# test = "fdfd1f风动旛动3"
# v = test.isalnum()
# print(v)

# 星号 判断字符串中是否只包含字母，数字，汉字
# test = "fdfdf风动旛动"
# v = test.isalpha()
# print(v)

# 判断字符串中是否是数字
# test = "123②"
# v = test.isdecimal()#②，特殊的不可以
# v1 = test.isdigit()#二，中文的数字不支持
# v2 = test.isnumeric()
# print(v,v1,v2)

# 数字  字母  下划线  标识符：def class
# test = "a123"
# v = test.isidentifier()#数字开头false
# print(v)

# 数字  字母  下划线  标识符：def class
# test = "a123"
# v = test.isidentifier()#数字开头false
# print(v)

# 是否存在不能打印的字符，比如\t,结果是false
# test = "a\t123"
# v = test.isprintable()
# print(v)

# 判断是否全部是空格
# test = "  \t"
# v = test.isspace()
# print(v)

# 判断是否是标题
# test = "the loneliest girl"
# v = test.istitle()
# print(v)
# v1 = test.title()
# print(v1)
# v2 = v1.istitle()
# print(v2)

# ***** 加入字符
# test = "_"
# value = "raitorei"
# v = test.join(value)#等于"".join(value)
# print(v)

# islower() 方法检测字符串是否由小写字母组成。
# isupper() 方法检测字符串中所有的字母是否都为大写。
# test1 = "abc"
# test2 = "abc123"
# test3 = "abc123A"
# v1 = test1.islower()
# v2 = test2.islower()
# v3 = test3.islower()
# print(v1,v2,v3)
# test4 = "ABC"
# test5 = "ABC123"
# test6 = "ABC123a"
# v4 = test4.isupper()
# v5 = test5.isupper()
# v6 = test6.isupper()
# print(v4,v5,v6)

# 变换大小写
# test = "asdfgh"
# v = test.upper()
# print(v)
# v = v.lower()
# print(v)

# 默认去除左右空格,\t,\n；可以指定字符
# test = " a s fgh "
# v = test.lstrip()
# print(v)
# v = test.rstrip()
# print(v)
# v = test.strip()
# print(v)
# v1 = v.strip("h")
# print(v1)

# 变换大小写
# test = "asdfgh"
# v = test.maketrans("asd","123")
# print(v)
# v1 = test.translate(v)
# print(v1)

# 分割字符，partition包含分隔符，split不包含分隔符
# test = "asdfghasdfghasdfgh"
# v1 = test.partition("f")
# print(v1)
# v2 = test.rpartition("f")
# print(v2)
# v3 = test.split("f",2)
# print(v3)
# v4 = test.rsplit("f",2)
# print(v4)

# 分割换行符，默认不包含分隔符(false)，true包含分隔符
# test = "asdfg\nhasd\nfghasdfgh"
# v1 = test.splitlines(True)
# print(v1)

# 分割换行符，默认不包含分隔符(false)，true包含分隔符
# test = "asdfg\nhasd\nfghasdfgh"
# v1 = test.splitlines(True)
# print(v1)

# 大小写转换
# test = "asdfghJKL"
# v1 = test.swapcase()
# print(v1)

#替换
test = "asdfghaJKaL"
# v1 = test.replace("a","b")
# print(v1)
# v2 = test.replace("a","b",2)
# print(v2)
################基本(7个)################
# join
# split
# find
# strip
# upper
# lower
# replace
################灰魔法(5个)################
test = "raitorei"
# #索引
# v1 = test[0]
# print(v1)

# #切片
# v2 = test[0:-1]
# print(v2)

# #长度
# v3 = len(test)
# print(v3)
# li = [1,2,3,4,5,"123"]
# print(len(li))

#循环输出
# index = 0
# while index < len(test) :
#     print(test[index])
#     index += 1
# print("---end---")

# for demo in test:
#     print(a)

#帮助创建数字,可以设置隔多少再创建
# v = range(0,100,5)
# print(v)
# for vv in v:
#     print(vv)
#将输入的文字的索引输出
value = input(">>>")
length = len(value)
num = range(0,length)
for f in num:
    print(f,value[f])

# *****注意：
    # 字符串一且自,不可修改。
    # 一且修改或者拼接,部会造成重新生成字符串