rpdfdata-extractionpdf-scrapingtabulizer

trying to scrape from long PDF with different table formats


I am trying to scrape from a 276-page PDF available here: https://www.acf.hhs.gov/sites/default/files/documents/ocse/fy_2018_annual_report.pdf

Not only is the document very long but it also has tables in different formats. I tried using the extract_tables() function in the tabulizer library. This successfully scrapes the data tables beginning on page 143 of the document but does not work for the tables on pages 18-75. Are these pages unscrapable? If so why?

I get error messages that say "more columns than column names" and "duplicate 'row.names' are not allowed"

child_support_scrape <- extract_tables(
  file   = "C:/Users/Jenny/Downloads/OCSE_2018_annual_report.pdf", 
  method = "decide", 
  output = "data.frame")

Solution

  • As texts in pdf files are not stored in plain text format. It is generally hard to extract text from a pdf file. The following method provide an alternative method to extract the table from the pdf. It requires the pdftools and plyr package.

    # Download the pdf file as a variable in R
    pdf_text <- pdftools::pdf_text("https://www.acf.hhs.gov/sites/default/files/documents/ocse/fy_2018_annual_report.pdf")
    
    # Focus on the table in page 22
    pdf_text22 <- strsplit(pdf_text[[22]], "\n")[[1]]
    
    # Reformat the table using "regular expression"
    pdf_text22 <- strsplit(pdf_text22, " {2,100}")
    
    # Convert the table in a data frame
    pdf_text22 <- plyr::rbind.fill(lapply(pdf_text22, function(x) as.data.frame(t(matrix(x)))))
    

    Additional formatting may be required to beautify the data frame.