def get_index(self, prefix='<STR_LIT>'):
if prefix:<EOL><INDENT>prefixed = '<STR_LIT>' % prefix<EOL><DEDENT>else:<EOL><INDENT>prefixed = '<STR_LIT:index>'<EOL><DEDENT>if prefixed in self.__cli and self.__cli[prefixed]:<EOL><INDENT>index = self.__cli.get(prefixed)<EOL>from_conf = False<EOL><DEDENT>else:<EOL><INDENT>index = self.__config.get(prefixed)<EOL>from_conf = True<EOL><DEDENT>return self.__abspath(index, from_conf)<EOL>
Retrieve the absolute path to an index, according to
`prefix`.

Args:
    prefix: str, the desired prefix or `None`.

Returns:
    str: An absolute path, or `None`