我想替换除了第一个连续点以外的所有点.这是我想要的一个例子：
> names.orig <- c("test & best","test & worse &&&& ? do")
> names <- make.names(names.orig)
> names
[1] "test...best" "test...worse.........do"
>
> # But I want this instead:
> # [1] "test.best" "test.worse.do"
>
> # Desperatley tried:
> gsub("\\.{2,}","",names)
[1] "testbest" "testworsedo"
> gsub("\\G((?!^).*?|[^\\.]*\\.*?)\\.",names)
Error in gsub("\\G((?!^).*?|[^\\.]*\\.*?)\\.",names) :
invalid regular expression '\G((?!^).*?|[^\.]*\.*?)\.',reason 'Invalid regexp'
> # etc.
>
> # The only thing that works for me is this
> unlist(lapply(strsplit(names,"\\."),function(x) paste(x[x != ""],collapse=".")))
[1] "test.best" "test.worse.do"
>
> # But,really,what is the right regex in combination with what?
如何用正则表达式解决这个问题？
解决方法
@H_404_18@ 将“”替换为“.”在你的第一个正则表达式：R> nms <- make.names(c("test & best","test & worse &&&& ? do"))
R> gsub("\\.{2,".",nms)
[1] "test.best" "test.worse.do"
这也有效.基本上,您用一个点替换所有点和连续点.
R> gsub("\\.+",nms)
[1] "test.best" "test.worse.do"
