用模式替换 R 中的字符串并替换两个向量 [英] Replace string in R with patterns and replacements both vectors

问题描述

假设我有两个这样的向量:

Let's say I have two vectors like so:

a <- c("this", "is", "test")
b <- c("that", "was", "boy")

我也有一个像这样的字符串变量:

I also have a string variable like so:

string <- "this is a story about a test"

我想替换字符串中的值，使其变为以下内容:

I want to replace values in string so that it becomes the following:

string <- "that was a story about a boy"

我可以使用 for 循环来做到这一点，但我希望将其矢量化.我该怎么做?

I could do this using a for loop but I want this to be vectorized. How should I do this?

推荐答案

如果您愿意使用非基础包，stringi 在这里非常有效:

If you're open to using a non-base package, stringi will work really well here:

stringi::stri_replace_all_fixed(string, a, b, vectorize_all = FALSE)
#[1] "that was a story about a boy"

请注意，这也适用于长度 > 1 的输入字符串.

Note that this also works the same way for input strings of length > 1.

为了安全起见，您可以对此进行调整 - 类似于 RUser 的回答 - 在替换之前检查单词边界:

To be on the safe side, you can adapt this - similar to RUser's answer - to check for word boundaries before replacing:

stri_replace_all_regex(string, paste0("\\b", a, "\\b"), b, vectorize_all = FALSE)

例如，这将确保您不会意外地将 his 替换为 hwas.

This would ensure that you don't accidentally replace his with hwas, for example.

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