如何在两个字符串中逐句查找不同的单词？

Question

我正在比较两个相似的文本。 x1是模型文本，x2是有错误的文本（例如，拼写，新字符等）。我正在尝试删除两个文本中的单词。由于我的实际文字不是英语，因此无法使用字典。

我尝试过的是逐步浏览x1的每个字符，如果它与x2中的相同，则从x2中删除并移至x1的下一个字符。

我一直在研究的代码：

x1 <- "This is a test. Weather is fine. What do I do? I am clueless this coding. Let’s do this as soon as possible." 
x2 <- "This text is a test. This weather is fine. What id I do? I am clueless thius coding. Ley’s do ythis as soon as possiblke."

library(tidyverse)
x1 <- str_split(x1, "(?<=\\.)\\s")
x1 <- lapply(x1,tolower)
x2 <- str_split(x2, "(?<=\\.)\\s")
x2 <- lapply(x2,tolower)

delete_a_from_b <- function(a,b) {

  a_as_list <- str_remove_all(a,"word") %>% 
    str_split(boundary("character")) %>% unlist

  b_n <- nchar(b)

  b_as_list <- str_remove_all(b,"word") %>% 
    str_split(boundary("character")) %>% unlist

  previous_j <-1

  for (i in 1:length(a_as_list)) {
    if(previous_j > length(b_as_list)) 
      break
    for (j in previous_j:length(b_as_list)){
      if(a_as_list[[i]]==b_as_list[[j]]){
        b_as_list[[j]] <- ""
        previous_j <- j+1
        break
      }
    }
  }

  print(paste0(b_as_list,collapse = ""))
  paste0(b_as_list,collapse = "")
}

x3 <- delete_a_from_b(x1,x2)
x3 <- strsplit(x3,"\\s")

输出：

x3
[[1]]
 [1] "text"       "this"       "i"          "i"          "d?am"       "clueless"   "thius"      "coing.\"," 
 [9] "\"ley’s"    "dythsssoon" "as"         "possibk"   

我想要的结果是：'text' 'this' 'id' 'thius' 'ley’s' 'ythis' 'possiblke'

Answer 1

认为我做到了，这是您需要的吗？

x1 <- "This is a test. Weather is fine. What do I do? I am clueless this coding. Let’s do this as soon as possible." 
x2 <- "This text is a test. This weather is fine. What id I do? I am clueless thius coding. Ley’s do ythis as soon as possiblke."

x1_w<-strsplit(paste(x1, collapse = " "), ' ')[[1]]
x2_w<-strsplit(paste(x2, collapse = " "), ' ')[[1]]
x1<- lapply(x1,tolower)
x2<- lapply(x2,tolower)

`%notin%` <- Negate(`%in%`)

x2_w[which(x2_w %notin% x1_w)]
# same as:
setdiff(x2_w,x1_w)

# out:

#> x2_w[which(x2_w %notin% x1_w)]
#[1] "text"       "id"         "thius"      "ley’s"      "ythis"      "possiblke."

Answer 2

我想你想比较两个字符串x1和x2 按句子-问题中不是很清楚。先前的解决方案没有考虑到这一点。试试这个：

首先拆分，两个字符串都变成句子：

x1_sentences <- unlist(strsplit(tolower(x1), split = "[.?!] "))
x2_sentences <- unlist(strsplit(tolower(x2), split = "[.?!] "))
length(x1_sentences)  == length(x2_sentences) # Make sure same number of resulting sentences

然后，对于每个句子，再次拆分两个向量，并在单词上显示差异：

for (i in 1:length(x1_sentences)) {
  x1_vector <- unlist(strsplit(x1_sentences[i], split = "[ ]"))
  x2_vector <- unlist(strsplit(x2_sentences[i], split = "[ ]"))
  print(setdiff(x2_vector, x1_vector)) # The order here is important!
}

提供（您可以轻松地将其转换为新向量）：

[1] "text"
[1] "this"
[1] "id"
[1] "thius"
[1] "ley’s"      "ythis"      "possiblke."