How do I get the metric in on_validation_epoch_end()?

LightningModule
1 
def validation_step(self, batch, batch_idx, dataloader_idx=None):
       I calculate metrci here.
      metric = XXXX

 def on_validation_epoch_end(self):

        I would like to get the metric here .
2

I answered a similar question here: How to access the returned values of *_step()
The same answer applies to all *_epoch_end hooks, including validation.

3

Well, this means that I need to collect the information at validation_step and then recalculate the metric at the on_validation_epoch_end.

My intention is that I often log the metric at validation_step , and it would be nice if the user could access the metric Lightning has calculated at on_validation_epoch_end.

    def validation_step(self, batch, batch_idx, dataloader_idx=None):
        f1, precision, recall, acc, current_batch_size = self.share_val_step(batch)
        metrics = {'val_acc': acc, 'val_f1': f1, 'val_precision': precision, 'val_recall': recall}
         # log metric
        self.log_dict(metrics, prog_bar=True, logger=True, on_epoch=True,
                      rank_zero_only=True, batch_size=current_batch_size)

    def on_validation_epoch_end(self):
        # Access to the metric Lightning has calculated