检查字符串匹配中的多个单词以在 r 中进行文本搜索

Question

目前我有一个用于单词搜索的代码，我们可以搜索多个词并将这些匹配的词写入数据框吗？（有关说明，请参阅此 ) this is 解决方案，该解决方案适用于一个词。这是代码：

 library(pdftools)
 library(tesseract)

 All_files <- Sys.glob("*.pdf")
 v1     <- numeric(length(All_files))
 word   <- "school"
 df     <- data.frame()
 Status <- "Present"

for (i in seq_along(All_files)){
  file_name <- All_files[i]

  cnt <- pdf_info(All_files[i])$pages
  print(cnt)
  for(j in seq_len(cnt)){
      img_file <- pdftools::pdf_convert(All_files[i], format = 'tiff', pages = j, dpi = 400)
      text     <- ocr(img_file)
      ocr_text <- capture.output(cat(text))
      check    <- sapply(ocr_text, paste, collapse="")
      junk     <- dir(path= paste0(path, "/tiff"), pattern="tiff")
      file.remove(junk)
      br <-if(length(which(stri_detect_fixed(tolower(check),tolower(word)))) <= 0) "Not Present"  
              else "Present" 
      print(br)       
      if(br=="Present") {
         v1[i] <- j
         break}
    }

    Status <- if(v1[i] == 0) "Not Present" else "Present"
    pages  <- if(v1[i] == 0) "-" else 
      paste0(tools::file_path_sans_ext(basename(file_name)), "_", v1[i])
    words  <- if(v1[i] == 0) "-" else word
    df     <- rbind(df, cbind(file_name = basename(file_name),
                    Status, pages = pages, words = words))
}

这里我们只搜索一个词，即school。我们可以搜索 school、gym、swimming pool 等多个词吗？

预计O/P

fileName   Status        Page             Words                    TEXT
test.pdf   Present     test_1             gym            I go gym regularly  
test.pdf   Present     test_3             school     Here is the next school
test1.pdf  Present     test1_4            swimming pool  In swimming pool
test1.pdf  Present     test1_7            gym         next to Gold gym
test2.pdf  Not Present    -               -

文件名=文件名

状态=如果找到任何单词则 "Present" else "Not Present"

Page=这里"_1","_3"定义了找到这个词的页码；;在第 "test_1" 页上找到了单词 "gym"，在第 "test_3" 页上找到了单词 "school"。

字数=找到所有字;;就像在 test.pdf 文件的第 1 页和第 3 页上只找到 "gym" 和 "school" 并且在 [=] 的第 4 页和第 7 页上只找到 "swimming pool" 和 "gym" 61=] 文件.

TEXT = 找到单词的文本

对此的任何建议都会有所帮助。

谢谢

Answer 1

您使用外部循环遍历目录中的每个 PDF。然后浏览 PDF 的所有页面并提取内循环中的文本。您想要检查每个文档是否至少有一页包含 school、gym 或 swimming pool。您要使用的返回值是：

包含 Present 或 Not present.
带有一些字符串的三个向量，包含关于哪个单词出现在何时何地的信息。

对吗？

您可以跳过循环中的几个步骤，尤其是在使用 ocr:

将 PDF 转换为 TIFF 并从中读取文本时

all_files <- Sys.glob("*.pdf")
strings   <- c("school", "gym", "swimming pool")

# Read text from pdfs
texts <- lapply(all_files, function(x){
                img_file <- pdf_convert(x, format="tiff", dpi=400)
                return( tolower(ocr(img_file)) )
                })

# Check for presence of each word in checkthese
pages <- words <- vector("list", length(texts))
for(d in seq_along(texts)){
  for(w in seq_along(strings)){
    intermed   <- grep(strings[w], texts[[d]])
    words[[d]] <- c(words[[d]], 
                    strings[w][ (length(intermed) > 0) ])
    pages[[d]] <- unique(c(pages[[d]], intermed))
  }
}

# Organize data so that it suits your wanted output
fileName <- tools::file_path_sans_ext(basename(all_files))

Page <- Map(paste0, fileName, "_", pages, collapse=", ")
Page[!grepl(",", Page)] <- "-"
Page <- t(data.frame(Page))

Words    <- sapply(words, paste0, collapse=", ")
Status   <- ifelse(sapply(Words, nchar) > 0, "Present", "Not present")

data.frame(row.names=fileName, Status=Status, Page=Page, Words=Words)        
#       Status                                   Page                      Words
# pdf1 Present                         pdf1_1, pdf1_2         gym, swimming pool
# pdf2 Present pdf2_2, pdf2_5, pdf2_8, pdf2_3, pdf2_6 school, gym, swimming pool

它不像我希望的那样可读。可能是因为要求不高w.r.t。输出需要一些小的中间步骤，使代码看起来有点混乱。它运作良好，但

检查字符串匹配中的多个单词以在 r 中进行文本搜索

Check for multiple words in string match for text search in r

ocr

search

r

dataframe