          lines = f.read().split('\n')
  
      _unnumber_chaps_and_secs(lines)
      _sec_to_chap(lines)
      lines = _delete_discussions_title(lines)
  
      with open(tex_file, 'w') as f:
          f.write('\n'.join(lines))
  
      pdf_dir = os.path.dirname(tex_file)
 
</s> remove                       '\\section{Exercises',
                      '\\section{Discussions',
 </s> add                       '\\section{Exercises' </s> remove                       '\\subsection{Exercises',
                      '\\subsection{Discussions'}
 </s> add                       '\\subsection{Exercises'}
    #lines = _delete_discussions_title(lines)
          lines = f.read().split('\n')
  
      _unnumber_chaps_and_secs(lines)
      _sec_to_chap(lines)
    #lines = _delete_discussions_title(lines)
  
      with open(tex_file, 'w') as f:
          f.write('\n'.join(lines))
  
      pdf_dir = os.path.dirname(tex_file)
keep keep keep keep replace keep keep keep keep keep
 re-enable discussion section as numbered 
static/post_latex/main.py