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使用R从文本中提取子字符串_R_Regex_Gsub - Fatal编程技术网
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使用R从文本中提取子字符串

r regex

使用R从文本中提取子字符串,r,regex,gsub,R,Regex,Gsub,我有一个字符串数据，如下所示： a<- "\n Update Your Profile to Dissolve This Message\nSocial Media Learning and behaviour\n Uploaded on May 3, 2020 at 10:56 in Research\n View Forum\n \n" 这给了我如下的输出 "Social Media Learning and behaviou

我有一个字符串数据，如下所示：

a<-  "\n    Update Your Profile to Dissolve This Message\nSocial Media Learning and behaviour\n        Uploaded on May 3, 2020 at 10:56 in Research\n            View Forum\n        \n"
这给了我如下的输出

"Social Media Learning and behaviour\n\n"
我无法匹配确切的模式。没有“\n\n”

的情况下，提取“社交媒体学习和行为”的确切模式是什么？您可以提取
“更新您的个人资料以消除此消息”
和
“上传到”

您也可以从
stringr

stringr::str_match(a, "Update Your Profile to Dissolve This Message\n(.*)\n\\s+Uploaded on")[, 2]
您可以捕获组中的前一行，并与包含以下内容的下一行匹配：

(.*)\r?\n[^\S\r\n]+Uploaded on


a您还可以匹配捕获组中的前一行，并匹配包含上载的
^（.*）\r？\n上载的


stringr::str_match(a, "Update Your Profile to Dissolve This Message\n(.*)\n\\s+Uploaded on")[, 2]



(.*)\r?\n[^\S\r\n]+Uploaded on



a<-  "\n    Update Your Profile to Dissolve This Message\nSocial Media Learning and behaviour\n        Uploaded on May 3, 2020 at 10:56 in Research\n            View Forum\n        \n"
stringr::str_match(a, "(.*)\\r?\\n[^\\S\\r\\n]+Uploaded on")