def _load_yaml(self):
        """lazy-import PyYAML so that configargparse doesn't have to dependend
        on it unless this parser is used."""
        try:
            import yaml
        except __HOLE__:
            raise ConfigFileParserException("Could not import yaml. "
                "It can be installed by running 'pip install PyYAML'")

        return yaml
dataset/ETHPy150Open bw2/ConfigArgParse/configargparse.py/YAMLConfigFileParser._load_yaml