本文实例讲述了python开发之字符串string操作方法。分享给大家供大家参考,具体如下:
在python中,对于字符串string的操作,我们有必要了解一下,这样在我们的以后的开发中会给我们带来很多方便
下面是我学习的笔记:
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#python-string #python中的字符串用单引号''和双引号""标示 strA = 'this is a string' strB = "this is a message!" #打印两个字符串 print ( "打印两个字符串" ) print ( 'strA = ' + strA) print ( 'strB = ' + strB) print ( "#############################" ) strC = 'I don\'t know anything' strD = '\'Yes\',I know.' print ( "字符串中的转义字符" ) print ( 'strA = ' + strC) print ( 'strB = ' + strD) print ( "#############################" ) strE = '这是我的blog,欢迎大家来\n我的博客溜达' print ( "字符串中的换行" ) print ( 'strA = ' + strE) print ( "#############################" ) strF = 'this is ' 'message' strG = 'Hongten' strH = strG * 3 print ( '字符串可以用\'+\'号连接(或者说粘合),也可以用\'*\'号循环' ) print ( 'strF原有形式为:\'this is \'\'message\'' ) print ( '粘合后的strF:' + strF) print ( 'strG原值为:\'Hongten\',strH = strG * 3,此时strH为:' + strH) print ( "#############################" ) strI = 'hongtenzone@foxmail.com' print ( '字符串可以使用下标(索引)查询' ) print ( '源字符串strI = \'hongtenzone@foxmail.com\'' ) print ( '字符串strI的长度,len(strI) = ' ) print ( len (strI)) print ( 'strI[0] = ' + strI[ 0 ]) print ( 'strI[10] = ' + strI[ 10 ]) print ( 'strI[-1] = strI[len(strI) - 1]' ) print ( 'strI[-1] = ' + strI[ - 1 ]) print ( 'strI[len(strI) - 1] = ' + strI[ len (strI) - 1 ]) print ( "#############################" ) print ( 'Python 字符串不能改写。按字符串索引赋值会产生错误:' ) print ( 'strI[0] = \'x\',这样就会产生错误啦' ) print ( "#############################" ) print ( '过大的索引代替为字符串大小,下界比上界大的返回空字符串' ) print ( 'strI[0:100] = ' + strI[ 0 : 100 ]) print ( "#############################" ) print ( '索引可以是负数,计数从右边开始' ) print ( 'strI[-2] = ' + strI[ - 2 ]) print ( 'strI[-23:] = ' + strI[ - 23 :]) print ( "#############################" ) print ( '不过-0 还是0,所以它不是从右边计数的!' ) print ( 'strI[0] = ' + strI[ 0 ]) print ( 'strI[-0] = ' + strI[ - 0 ]) |
运行效果如下:
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Python 2.7 . 9 (default, Dec 10 2014 , 12 : 24 : 55 ) [MSC v. 1500 32 bit (Intel)] on win32 Type "copyright" , "credits" or "license()" for more information. >>> = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = RESTART = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = >>> 打印两个字符串 strA = this is a string strB = this is a message! ############################# 字符串中的转移字符 strA = I don't know anything strB = 'Yes' ,I know. ############################# 字符串中的换行 strA = 这是我的blog,欢迎大家来 我的博客溜达 ############################# 字符串可以用 '+' 号连接(或者说粘合),也可以用 '*' 号循环 strF原有形式为: 'this is ' 'message' 粘合后的strF:this is message strG原值为: 'Hongten' ,strH = strG * 3 ,此时strH为:HongtenHongtenHongten ############################# 字符串可以使用下标(索引)查询 源字符串strI = 'hongtenzone@foxmail.com' 字符串strI的长度, len (strI) = 23 strI[ 0 ] = h strI[ 10 ] = e strI[ - 1 ] = strI[ len (strI) - 1 ] strI[ - 1 ] = m strI[ len (strI) - 1 ] = m ############################# Python 字符串不能改写。按字符串索引赋值会产生错误: strI[ 0 ] = 'x' ,这样就会产生错误啦 ############################# 过大的索引代替为字符串大小,下界比上界大的返回空字符串 strI[ 0 : 100 ] = hongtenzone@foxmail.com ############################# 索引可以是负数,计数从右边开始 strI[ - 2 ] = o strI[ - 23 :] = hongtenzone@foxmail.com ############################# 不过 - 0 还是 0 ,所以它不是从右边计数的! strI[ 0 ] = h strI[ - 0 ] = h >>> |
print打印字符串语句如下:
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print ( '理解切片的最好方式是把索引视为两个字符之间的点,第一个字符的左边是0,字符串中第n个字符的右边是索引n' ) print ( ' +---+---+---+---+---+ ' ) print ( ' | H | e | l | p | A |' ) print ( ' +---+---+---+---+---+ ' ) print ( ' 0 1 2 3 4 5 ' ) print ( '-5 -4 -3 -2 -1 -0' ) print ( '第一行是字符串中给定的0到5各个索引的位置,第二行是对应的负索引。从i 到j 的切片由这两个标志之间的字符组成' ) print ( '对于非负索引,切片长度就是两索引的差。例如,word[1:3] 的长度是2' ) |
运行效果如下:
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Python 2.7 . 9 (default, Dec 10 2014 , 12 : 24 : 55 ) [MSC v. 1500 32 bit (Intel)] on win32 Type "copyright" , "credits" or "license()" for more information. >>> = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = RESTART = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = >>> 理解切片的最好方式是把索引视为两个字符之间的点,第一个字符的左边是 0 ,字符串中第n个字符的右边是索引n + - - - + - - - + - - - + - - - + - - - + | H | e | l | p | A | + - - - + - - - + - - - + - - - + - - - + 0 1 2 3 4 5 - 5 - 4 - 3 - 2 - 1 - 0 第一行是字符串中给定的 0 到 5 各个索引的位置,第二行是对应的负索引。从i 到j 的切片由这两个标志之间的字符组成 对于非负索引,切片长度就是两索引的差。例如,word[ 1 : 3 ] 的长度是 2 >>> |
希望本文所述对大家Python程序设计有所帮助。