question: Accuracy doesn't show up in progress bar
context: class Mynet(pl.LightningModule)
      ... ...
      def training_step(self, batch, batch_idx):
          x, y = batch
          logits = self(x)
          loss = F.nll_loss(logits, y)
          accu = ((torch.argmax(logits, dim=1) == y).sum()/x.shape[0]).item()   
          return {'loss':loss, 'accuracy':accu}
  i define training_step like this, the progress bar show loss,  but not show accu.
  i want to know why?
  pytorch_lightning.version = 1.5.7
answer: You need to log it:
  self.log("accuracy", accu, prog_bar=True)
  return {'loss':loss}
  Docs: https://pytorch-lightning.readthedocs.io/en/latest/extensions/logging.html#logging-from-a-lightningmodule