parameters: (u_string)
docstring: Determine if unicode string only contains ASCII characters.
  
      :param str u_string: unicode string to check. Must be unicode
          and not Python 2 `str`.
      :rtype: bool
docstring_summary: Determine if unicode string only contains ASCII characters.
docstring_tokens: Determine if unicode string only contains ASCII characters .
function: def unicode_is_ascii(u_string):
      """Determine if unicode string only contains ASCII characters.
  
      :param str u_string: unicode string to check. Must be unicode
          and not Python 2 `str`.
      :rtype: bool
      """
      assert isinstance(u_string, str)
      try:
          u_string.encode('ascii')
          return True
      except UnicodeEncodeError:
          return False
function_tokens: def unicode_is_ascii ( u_string ) : assert isinstance ( u_string , str ) try : u_string . encode ( 'ascii' ) return True except UnicodeEncodeError : return False