正則表達式：替換兩個字符之間的所有空格

Question

考慮以下字符串： This is an example: this is another one, and this is yet another, and other, and so on.字符串， This is an example: this is another one, and this is yet another, and other, and so on.字符串This is an example: this is another one, and this is yet another, and other, and so on. 我想替換:和,之間的所有空格字符。 所以它看起來像這樣This is an example:_this_is_another_one, and this is yet another, and other, and so on.

到目前為止我嘗試過的：

• (?<=:)\\s+(?=[^,]*,) （只匹配第一個空格）
• :\\s+(?=[^:,]*,) （同上）
• \\s+(?=[^:,]*,) （匹配This is an example:_this_is_another_one,_and_this_is_yet_another,_and_other, and so on ）

Answer 1

更新：有一種簡單的方法可以使用stringr::str_replace_all使用匿名函數作為替換參數來替換 R 中任意字符串之間的任何內容：

通用stringr方法

library(stringr)

# left - left boundary
# right - right boundary
# x - input
# what - regex pattern to search for inside matches
# repl - replacement text for the in-pattern matches
ReplacePatternBetweenTwoStrings <- function(left, right, x, what, repl) {
  left  <- gsub("([][{}()+*^${|\\\\?.])", "\\\\\\1", left)
  right <- gsub("([][{}()+*^${|\\\\?.])", "\\\\\\1", right)
  str_replace_all(x, 
     paste0("(?s)(?<=", left, ").*?(?=", right, ")"),
     function(z) gsub(what, repl, z)
  )
}

x <- "This is an example: this is another one, and this is yet another, and other, and so on."
ReplacePatternBetweenTwoStrings(":", ",", x, "\\s+", "_")
## => [1] "This is an example:_this_is_another_one, and this is yet another, and other, and so on."

請參閱此 R 演示。

替換最近的:和 之間的所有空格,

這是上面的一個簡單的邊緣情況，當:[^:,]+,匹配 a : ，然后是除:和, （分隔符字符）之外的任意數量的字符，然后是 a , ，然后空格被替換為下划線僅比賽：

stringr::str_replace_all(x, ":[^:,]+,", function(z) gsub("\\s+", "_", z))

查看正則表達式演示

原始答案（比例相當差）

您可以使用以下正則表達式：

(?:\G(?!^)|:)[^,]*?\K\s(?=[^,]*,)

替換為_ 。 請參閱正則表達式演示。

詳情

• (?:\\G(?!^)|:) - 前一個匹配的結尾（ \\G(?!)^ ）或冒號
• [^,]*? - 除 之外的任何 0+ 個字符,盡可能少
• \\K - 匹配重置運算符丟棄到目前為止匹配的文本
• \\s - 一個空格
• (?=[^,]*,) - 一個積極的前瞻檢查，確保在零個或多個除逗號之外的字符之后有一個, 。

R演示：

re <- "(?:\\G(?!^)|:)[^,]*?\\K\\s(?=[^,]*,)"
x <- "This is an example: this is another one, and this is yet another, and other, and so on."
gsub(re, "_", x, perl=TRUE)
# => [1] "This is an example:_this_is_another_one, and this is yet another, and other, and so on."

Answer 2

這是一個略顯粗糙的答案：

txt="This is an example: this is another one, and this is yet"

split_str=unlist(strsplit(gsub("^(.*:)(.*)(,.*)", "\\1$\\2$\\3", txt), split="$", fixed=T))

paste0(split_str[1], gsub(" ", "_",split_str[2]), split_str[3])