text: from subprocess import call
  import glob
  
  from split_sentences import split_sentences
  
  # first convert .pdf to .txt using the command line utility pdftotext from Xpdf
  for folder in [
      'pdf_files/psa_research', 
      'pdf_files/chi_2018'
  ]:
      pdf_filepaths = glob.glob("{}/*.pdf".format(folder))
      for pdf_filepath in pdf_filepaths:
          txt_filepath = pdf_filepath.lower().replace("pdf_files", "txt_files").replace('.pdf', '.txt')
          call(["pdftotext", pdf_filepath, txt_filepath])
          split_sentences(txt_filepath)
          
  
  
  
  
  