code: def pynac_in_sub_directory(num, file_list):
          
          print('Running %d' % num)
          new_dir = 'dynacProc_%04d' % num
          if os.path.isdir(new_dir):
              shutil.rmtree(new_dir)
          os.mkdir(new_dir)
          for f in file_list:
              shutil.copy(f, new_dir)
          os.chdir(new_dir)
  
          yield
  
          os.chdir('..')
docs: A context manager to create a new directory, move the files listed in ``file_list``
          to that directory, and change to that directory before handing control back to
          context.  The closing action is to change back to the original directory.
  
          The directory name is based on the ``num`` input, and if it already exists, it
          will be deleted upon entering the context.
  
          The primary purpose of this function is to enable multiprocess use of Pynac via
          the ``multi_process_pynac`` function.