拆分由点连接的两个单词

Question

我有一个包含新闻文章的大数据框。我注意到有些文章有两个单词由点连接，如下例所示 The government.said it was important to quit.。我将进行一些主题建模，因此我需要将每个单词分开。

这是我用来分隔那些单词的代码

    #String example
    test <- c("i need.to separate the words connected by dots. however, I need.to keep having the dots separating sentences")

    #Code to separate the words
    test <- do.call(paste, as.list(strsplit(test, "\.")[[1]]))

   #This is what I get
  > test
  [1] "i need to separate the words connected by dots  however, I need to keep having the dots separating sentences"

如您所见，我删除了文本上的所有点（句点）。我怎样才能得到以下结果：

"i need to separate the words connected by dots. however, I need to keep having the dots separating sentences"

最后的注释

我的数据框由 17.000 篇文章组成；所有的文字都是小写的。我只是提供了一个小例子，说明我在尝试分隔由点连接的两个单词时遇到的问题。此外，有什么方法可以在列表中使用 strsplit 吗？

Answer 1

您可以使用

test <- c("i need.to separate the words connected by dots. however, I need.to keep having the dots separating sentences. Look at http://google.com for s.0.m.e more details.")
# Replace each dot that is in between word characters
gsub("\b\.\b", " ", test, perl=TRUE)
# Replace each dot that is in between letters
gsub("(?<=\p{L})\.(?=\p{L})", " ", test, perl=TRUE)
# Replace each dot that is in between word characters, but no in URLs
gsub("(?:ht|f)tps?://\S*(*SKIP)(*F)|\b\.\b", " ", test, perl=TRUE)

参见R demo online。

输出：

[1] "i need to separate the words connected by dots. however, I need to keep having the dots separating sentences. Look at http://google com for s 0 m e more details."
[1] "i need to separate the words connected by dots. however, I need to keep having the dots separating sentences. Look at http://google com for s.0.m e more details."
[1] "i need to separate the words connected by dots. however, I need to keep having the dots separating sentences. Look at http://google.com for s 0 m e more details."

详情

\b\.\b - 用单词边界包围的点（即 . 前后不能是任何非单词字符，除了字母、数字或下划线外不能有任何字符
(?<=\p{L})\.(?=\p{L}) 匹配前面或后面都没有字母的点（(?<=\p{L}) 是负向后视，(?=\p{L}) 是负向前视）
(?:ht|f)tps?://\S*(*SKIP)(*F)|\b\.\b 匹配 http/ftp 或 https/ftps，然后匹配 ://，然后是任何 0 个或多个非空白字符，并跳过匹配并继续搜索从遇到 SKIP PCRE 动词时的位置匹配。

拆分由点连接的两个单词

Split two words connected by a dot

regex

string

r

strsplit