def init_validation_tqdm(self) -> Tqdm:
        """Override this to customize the tqdm bar for validation."""
        # The train progress bar doesn't exist in `trainer.validate()`
        has_main_bar = self.trainer.state.fn != "validate"
        return Tqdm(
            desc=self.validation_description,
            position=(2 * self.process_position + has_main_bar),
            disable=self.is_disabled,
            leave=not has_main_bar,
            dynamic_ncols=True,
            file=sys.stdout,
            bar_format=self.BAR_FORMAT,
        )
Override this to customize the tqdm bar for validation.
src/lightning/pytorch/callbacks/progress/tqdm_progress.py