def compute_key_value(self) -> Dict[str, float]:
        """
        Compute metric for all data and return results in key-value format

        Returns:
            dict of metrics
        """
        means, stds = self.compute()
        output_mean = {
            f"{self.prefix}{self.metric_name}{key:02d}{self.suffix}": value
            for key, value in zip(self.topk, means)
        }
        output_std = {
            f"{self.prefix}{self.metric_name}{key:02d}{self.suffix}/std": value
            for key, value in zip(self.topk, stds)
        }
        return {**output_mean, **output_std}

        Compute metric for all data and return results in key-value format

        Returns:
            dict of metrics
        
catalyst/metrics/_topk_metric.py