code: def get_article(doi, output_format='txt'):
      
      xml_string = download_article(doi)
      if output_format == 'txt' and xml_string is not None:
          text = extract_text(xml_string)
          return text
      return xml_string
docs: Get the full body of an article from Elsevier.
  
      Parameters
      ----------
      doi : str
          The doi for the desired article.
      output_format : 'txt' or 'xml'
          The desired format for the output. Selecting 'txt' (default) strips all
          xml tags and joins the pieces of text in the main text, while 'xml'
          simply takes the tag containing the body of the article and returns it
          as is . In the latter case, downstream code needs to be able to
          interpret Elsever's XML format.
  
      Returns
      -------
      content : str
          Either text content or xml, as described above, for the given doi.