在R中替换单反斜杠 [英] substitute single backslash in R

问题描述

我已经在堆栈溢出中阅读了有关此主题的一些问题和答案，但仍然不知道如何解决这个问题：

I have read some questions and answers on this topic in stack overflow but still don't know how to solve this problem:

我的目的是转换文件Windows资源管理器中的目录字符串可以在R中可识别的形式，例如C：\Users\Public需要转换为C：/ Users / Public，基本上单斜杠应该用正斜杠代替。但是，R不能存储原始字符串C：\Users\Public，因为\U和\P被视为转义符。

My purpose is to transform the file directory strings in windows explorer to the form which is recognizable in R, e.g. C:\Users\Public needs to be transformed to C:/Users/Public, basically the single back slash should be substituted with the forward slash. However the R couldn't store the original string "C:\Users\Public" because the \U and \P are deemed to be escape character.

dirTransformer <- function(str){
   str.trns <- gsub("\\", "/", str)
   return(str.trns)
   }

str <- "C:\Users\Public"
dirTransformer(str)

> Error: '\U' used without hex digits in character string starting ""C:\U"

我实际写的是一个GUI，最终的效果是，用户将目录输入或粘贴到输入字段中，按下一个按钮，然后程序将自动处理。

What I am actually writing is a GUI, where the end effect is, the user types or pastes the directory into a entry field, pushes a button and then the program will process it automatically.

有人会建议我如何解决这个问题？

Would someone please suggest to me how to solve this problem?

推荐答案

当你需要使用反斜杠在R中的字符串中，您需要放置双反斜杠，此外，当您使用 gsub（\\，/，str）时，第一个参数被解析为正则表达式，它是无效的，因为它只包含一个必须转义的单个文字反斜杠。实际上，您需要使 gsub 将其视为纯文本与 fixed = TRUE 。

When you need to use a backslash in the string in R, you need to put double backslash. Also, when you use gsub("\\", "/", str), the first argument is parsed as a regex, and it is not valid as it only contains a single literal backslash that must escape something. In fact, you need to make gsub treat it as a plain text with fixed=TRUE.

但是，您可能想使用 normalizePath ，请参阅这个SO线程。

However, you might want to use normalizePath, see this SO thread.

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