code: def touch(filepath, times=None, mkdir=False):
      
      filepath = expand_path(filepath)
      if mkdir:
          mkdir_p(os.path.dirname(filepath))
      with open(filepath, 'a'):
          if times or times is None:
              os.utime(filepath, times)
      return filepath
docs: Update the modify (modify) and change (ctime) timestamps of a file, create if necessary
  
      >>> from pugnlp.constants import DATA_PATH
      >>> filepath = os.path.join(DATA_PATH, 'tmpfilefortouch.txt')
      >>> touch(filepath).endswith('tmpfilefortouch.txt')
      True
      >>> os.path.isfile(filepath)
      True
      >>> os.remove(filepath)