text: import shutil
  import os
  
  from datetime import datetime
  from typing import Optional
  
  
  def get_new_fname(fname: str, 
                    path_prefix: Optional[str]=None, 
                    path_postfix: Optional[str]=None) -> str:
      '''Creates a new input fname using the original
      replacing the extension to tsv
  
      # Arguments
          fname: original file name or path to file
          path_prefix: pwd path for the new file
          path_postfix: filename postfix
  
      # Returns
          new file's name
      '''
      fpath, fname = os.path.split(fname)
      fname, ext = os.path.splitext(fname)
      
      if path_prefix is None:
          fname = os.path.join(fpath, fname)
      else:
          fname = os.path.join(path_prefix, fname)
  
      if path_postfix is not None:
          fname = '_'.join([fname, path_postfix])
  
      fname = '.'.join([fname, 'tsv'])
      return fname
  
  
  def create_new_folder(path, path_postfix, rmdir_old=True):
      '''Creates a new folder using the input path by adding
      to it a `path_postfix`. 
  
      If the directory with the choosed name exists 
      removes it or not depending on `rmdir_old` parameter
  
      # Arguments
          path: string, path to the original directory
          path_postfix: string, will be added to original to create new name
          rmdir_old: boolean, whether or not to remove old dir
  
      # Returns 
          string, name of the created folder
      '''
      dir_to_save = '_'.join([path, path_postfix])
  
      if not os.path.isdir(dir_to_save):
          os.mkdir(dir_to_save)
          print("Folder '%s' was created" % dir_to_save)
          return dir_to_save
  
      if rmdir_old:
          print("Folder with such name exists, remove it")
          shutil.rmtree(dir_to_save)
  
      if not rmdir_old:
          datetime_now = datetime.now().strftime("%Y-%m-%d_%H-%M-%S")
          dir_to_save = '_'.join([dir_to_save, datetime_now])
  
      os.mkdir(dir_to_save)
      print("Folder '%s' was created" % dir_to_save)
      return dir_to_save