如何在多行中替換單個字線？

Question

我有一些字符串的數據框。 有些行有一個單詞，我想用空白代替。 我能夠檢索到該詞，但是在替換它們時，我會收到警告消息

警告消息：在gsub（pattern = text [lengths（gregexpr（“ [[:::]] +”，text））==中：參數'pattern'的長度> 1，並且僅使用第一個元素

只有第一個單詞會被替換，其余單詞將保持原樣。 我想替換數據框中的所有單個單詞。

我正在使用的代碼如下。

text <- c("Because I could not stop for Death -",
          "Word1",
          "He kindly stopped for me -",
          "Word2",
          "The Carriage held but just Ourselves - ",
          "word3",
          "and Immortality")

gsub(pattern = text[lengths(gregexpr("[[:alpha:]]+", text)) == 1], "", text)

我期望低於輸出。

"Because I could not stop for Death -",
          "He kindly stopped for me -",
          "The Carriage held but just Ourselves - ",
          "and Immortality"

Answer 1

一個簡單的邏輯索引就可以解決問題，因為您要保留的單詞似乎位於1、3、5，...等位置，即

text[c(TRUE, FALSE)]
#[1] "Because I could not stop for Death -"    "He kindly stopped for me -"             
#[3] "The Carriage held but just Ourselves - " "and Immortality"

Answer 2

a=gsub("^\\w+$","",text)
[1] "Because I could not stop for Death -"    ""                                       
[3] "He kindly stopped for me -"              ""                                       
[5] "The Carriage held but just Ourselves - " ""                                       
[7] "and Immortality"   

grep("\\w",a,value = T)
[1] "Because I could not stop for Death -"    "He kindly stopped for me -"             
[3] "The Carriage held but just Ourselves - " "and Immortality"  

或者你可以簡單地做

grep("\\w+\\s",text,value = T)
[1] "Because I could not stop for Death -"    "He kindly stopped for me -"             
[3] "The Carriage held but just Ourselves - " "and Immortality"  

Answer 3

您能否嘗試遵循並讓我知道這是否對您有幫助。

text <- c("Because I could not stop for Death -",
          "Word1",
          "He kindly stopped for me -",
          "Word2",
          "The Carriage held but just Ourselves - ",
          "word3",
          "and Immortality")

獲取OP所需輸出的代碼：

text[!grepl("[Ww]ord[0-9]+", text)] 

輸出如下。

[1] "Because I could not stop for Death -"    "He kindly stopped for me -"             
[3] "The Carriage held but just Ourselves - " "and Immortality"

對於來自幫助頁面的grepl ：

grepl返回邏輯向量（是否匹配x的每個元素）。