Is trainer.callback_metrics after trainer.fit() of the last epoch?

[libokj]

Is trainer.callback_metrics accessed after a trainer.fit call the logged metrics of the last epoch? Or is it the metrics of the best checkpoint if ModelCheckpoint is included in the callbacks?

[libokj]

Never mind. Found the answers by reading the source code. Calling trainer.callback_metrics after trainer.fit() will always return the metrics of the latest training epoch and validation epoch (if any).

There doesn't seem to be a straightforward way to get the training and validation metrics of the best model as monitored by ModelCheckpoint, but I think a custom callback based on ModelCheckpoint to save the best_model_metrics or simply running trainer.test(..., ckpt='best') on the training and validation datasets respectively are two viable options.