def delete_unused_cache_files(self, meta_data, meta_data_cache):
        old_files_to_delete = (set(meta_data_cache.iterkeys()) - set(meta_data.iterkeys()))
        if old_files_to_delete:
            gzip_cache_dir = self.get_gzip_dir()
            for relative_path in old_files_to_delete:
                cache_file_name = '%s/%s.gz' % (gzip_cache_dir, relative_path)
                if access(cache_file_name, R_OK):
                    remove(cache_file_name)
dataset/ETHPy150Open turbulenz/turbulenz_local/turbulenz_local/lib/deploy.py/Deployment.delete_unused_cache_files/original