Configurable metric formatting for RichProgressBar (#18373)

docs/source-pytorch/common/progress_bar.rst

@@ -93,6 +93,7 @@ Customize the theme for your :class:`~lightning.pytorch.callbacks.RichProgressBa
             processing_speed="grey82",
             metrics="grey82",
             metrics_text_delimiter="\n",
+            metrics_format=".3e",
         )
     )
 

src/lightning/pytorch/CHANGELOG.md

@@ -9,6 +9,8 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 
 ### Added
 
+- Added `metrics_format` attribute to `RichProgressBarTheme` class ([#18373](https://github.com/Lightning-AI/lightning/pull/18373))
+
 - Added `CHECKPOINT_EQUALS_CHAR` attribute to `ModelCheckpoint` class ([#17999](https://github.com/Lightning-AI/lightning/pull/17999))
 
 - Added `**summarize_kwargs` to `ModelSummary` and `RichModelSummary` callbacks ([#16788](https://github.com/Lightning-AI/lightning/pull/16788))

src/lightning/pytorch/callbacks/progress/rich_progress.py

@@ -136,13 +136,20 @@ if _RICH_AVAILABLE:
     class MetricsTextColumn(ProgressColumn):
         """A column containing text."""
 
-        def __init__(self, trainer: "pl.Trainer", style: Union[str, "Style"], text_delimiter: str):
+        def __init__(
+            self,
+            trainer: "pl.Trainer",
+            style: Union[str, "Style"],
+            text_delimiter: str,
+            metrics_format: Union[str, None],
+        ):
             self._trainer = trainer
             self._tasks: Dict[Union[int, TaskID], Any] = {}
             self._current_task_id = 0
             self._metrics: Dict[Union[str, "Style"], Any] = {}
             self._style = style
             self._text_delimiter = text_delimiter
+            self._metrics_format = metrics_format
             super().__init__()
 
         def update(self, metrics: Dict[Any, Any]) -> None:
@@ -173,8 +180,10 @@ if _RICH_AVAILABLE:
             return Text(text, justify="left", style=self._style)
 
         def _generate_metrics_texts(self) -> Generator[str, None, None]:
-            for k, v in self._metrics.items():
-                yield f"{k}: {round(v, 3) if isinstance(v, float) else v}"
+            for name, value in self._metrics.items():
+                if not isinstance(value, str):
+                    value = round(value, 3) if self._metrics_format is None else f"{value:{self._metrics_format}}"
+                yield f"{name}: {value}"
 
 else:
     Task, Style = Any, Any  # type: ignore[assignment, misc]
@@ -207,6 +216,7 @@ class RichProgressBarTheme:
     processing_speed: Union[str, Style] = "grey70"
     metrics: Union[str, Style] = "white"
     metrics_text_delimiter: str = " "
+    metrics_format: Union[str, None] = None
 
 
 class RichProgressBar(ProgressBar):
@@ -328,7 +338,12 @@ class RichProgressBar(ProgressBar):
             reconfigure(**self._console_kwargs)
             self._console = get_console()
             self._console.clear_live()
-            self._metric_component = MetricsTextColumn(trainer, self.theme.metrics, self.theme.metrics_text_delimiter)
+            self._metric_component = MetricsTextColumn(
+                trainer,
+                self.theme.metrics,
+                self.theme.metrics_text_delimiter,
+                self.theme.metrics_format,
+            )
             self.progress = CustomProgress(
                 *self.configure_columns(trainer),
                 self._metric_component,