code: def file_handle(fnh, mode="rU"):
      
      handle = None
      if isinstance(fnh, file):
          if fnh.closed:
              raise ValueError("Input file is closed.")
          handle = fnh
      elif isinstance(fnh, str):
          handle = open(fnh, mode)
  
      return handle
docs: Takes either a file path or an open file handle, checks validity and returns an open
      file handle or raises an appropriate Exception.
  
      :type fnh: str
      :param fnh: It is the full path to a file, or open file handle
  
      :type mode: str
      :param mode: The way in which this file will be used, for example to read or write or
                   both. By default, file will be opened in rU mode.
  
      :return: Returns an opened file for appropriate usage.