code: def secret(prompt=None, empty=False):
      
      if prompt is None:
          prompt = PROMPT
      s = getpass.getpass(prompt=prompt)
      if empty and not s:
          return None
      else:
          if s:
              return s
          else:
              return secret(prompt=prompt, empty=empty)
docs: Prompt a string without echoing.
  
      Parameters
      ----------
      prompt : str, optional
          Use an alternative prompt.
      empty : bool, optional
          Allow an empty response.
  
      Returns
      -------
      str or None
          A str if the user entered a non-empty string.
          None if the user pressed only Enter and ``empty`` was True.
  
      Raises
      ------
      getpass.GetPassWarning
          If echo free input is unavailable.
  
      See Also
      --------
      getpass.getpass