code: def load_content(self):
          
  
          # get the toc file from the root file
          rel_path = self.root_file_url.replace(os.path.basename(self.root_file_url), '')
          self.toc_file_url = rel_path + self.root_file.find(id="ncx")['href']
          self.toc_file_soup = bs(self.book_file.read(self.toc_file_url), 'xml')
  
          # get the book content from the toc file
  
          for n, c in cross(self.toc_file_soup.find_all('navLabel'), self.toc_file_soup.find_all('content')):
              content_soup = bs(self.book_file.read(rel_path + c.get('src')))
              self.content.append({'part_name': c.text,
                                   'source_url': c.get('src'),
                                   'content_source': content_soup,
                                   'content_source_body': content_soup.body,
                                   'content_source_text': content_soup.body.text})
docs: Load the book content