docs: def run(self):
          """Render and display Python package documentation.
          """
          os.environ['JARN_RUN'] = '1'
          self.python.check_valid_python()
  
          args = self.parse_options(self.args)
          if args:
              arg = args[0]
          else:
              arg = os.curdir
          if arg:
              arg = expanduser(arg)
  
          if isfile(arg):
              outfile = self.render_file(arg)
          elif isdir(arg):
              outfile = self.render_long_description(arg)
          else:
              err_exit('No such file or directory: %s' % arg)
  
          self.open_in_browser(outfile)