更改字符串在 R 中较大字符串中的位置

Question

我有一个字符列，看起来像这样：

names <- c("Isle North East", "London Northwestern", "Bedfordshire North East", "Southwark and Bermondsey North East",
           "Middlesbrough South and Cleveland East")

我想做的是将表达式 "North East" 移动到出现在它之前的任何单词之前。因此，如果字符串是 XXXX XXXX North East，我希望它是“XXXX North East XXXX”。如果我展示我正在寻找的解决方案，也许会更容易：

ideal.names <- c("North East Isle", "London Northwestern", "North East Bedfordshire", "Southward and North East Bermondsey",
             "Middlesbrough South and Cleveland East")

我正在尝试不同的方法，例如：

c(sub('^(.*) North East', 'North East \1', names))

但是这个returns以下：

[1] "North East Isle"                        "London Northwestern"                   
[3] "North East Bedfordshire"                "North East Southwark and Bermondsey"   
[5] "Middlesbrough South and Cleveland East"

所以问题在于，这会将字符串 North East 移动到字符串的开头，而不是在其前面的单词之前。所以我得到 North East Southwark and Bermondsey 而不是 Southward and North East Bermondsey，这正是我想要的。任何帮助都会很棒。谢谢！

Answer 1

您可以使用

gsub('(\S+) (North East)', '\2 \1', names)
## => [1] "North East Isle"                        "London Northwestern"                    "North East Bedfordshire"                "Southwark and North East Bermondsey"   
##    [5] "Middlesbrough South and Cleveland East"

详情

(\S+) - 第 1 组 (</code>)：一个或多个非白人space</li> <li><code> - 一个space
(North East) - 第 2 组 (</code>)：<code>North East 字符串。

参见regex demo。

更改字符串在 R 中较大字符串中的位置

Change the position of string within a larger string in R

regex

string

r

stringr