truncate long version number in progress bar (#2594)

* truncate version number

* add docs and example

* extend docs

* docs

* docs

* changelog

* show last

* Update pytorch_lightning/core/lightning.py

* Update pytorch_lightning/core/lightning.py

Co-authored-by: William Falcon <waf2107@columbia.edu>

CHANGELOG.md

@@ -16,6 +16,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 
 ### Changed
 
+- Truncated long version numbers in progress bar ([#2594](https://github.com/PyTorchLightning/pytorch-lightning/pull/2594))
 
 ### Deprecated
 

docs/source/experiment_reporting.rst

@@ -30,14 +30,14 @@ Control log writing frequency
 Writing to a logger  can be expensive. In Lightning you can set the interval at which you
 want to log using this trainer flag.
 
-.. seealso::
-    :class:`~pytorch_lightning.trainer.trainer.Trainer`
-
 .. testcode::
 
     k = 100
     trainer = Trainer(log_save_interval=k)
 
+.. seealso::
+    :class:`~pytorch_lightning.trainer.trainer.Trainer`
+
 ----------
 
 Log metrics
@@ -94,10 +94,14 @@ For instance, here we log images using tensorboard.
 Modify progress bar
 ^^^^^^^^^^^^^^^^^^^
 
-Each return dict from the training_end, validation_end, testing_end and training_step also has
-a key called "progress_bar".
+Each return dict from the
+:meth:`~pytorch_lightning.core.lightning.LightningModule.training_step`,
+:meth:`~pytorch_lightning.core.lightning.LightningModule.training_epoch_end`,
+:meth:`~pytorch_lightning.core.lightning.LightningModule.validation_epoch_end` and
+:meth:`~pytorch_lightning.core.lightning.LightningModule.test_epoch_end`
+can also contain a key called `progress_bar`.
 
-Here we show the validation loss in the progress bar
+Here we show the validation loss in the progress bar:
 
 .. testcode::
 
@@ -109,6 +113,10 @@ Here we show the validation loss in the progress bar
         results = {'progress_bar': logs}
         return results
 
+The progress bar by default already includes the training loss and version number of the experiment
+if you are using a logger. These defaults can be customized by overriding the
+:meth:`~pytorch_lightning.core.lightning.LightningModule.get_progress_bar_dict` hook in your module.
+
 
 ----------
 

pytorch_lightning/core/lightning.py

@@ -1544,7 +1544,6 @@ class LightningModule(ABC, DeviceDtypeModuleMixin, GradInformation, ModelIO, Mod
         Example:
             .. code-block:: python
 
-
                 def on_save_checkpoint(self, checkpoint):
                     # 99% of use cases you don't need to implement this method
                     checkpoint['something_cool_i_want_to_save'] = my_cool_pickable_object
@@ -1558,7 +1557,23 @@ class LightningModule(ABC, DeviceDtypeModuleMixin, GradInformation, ModelIO, Mod
 
     def get_progress_bar_dict(self) -> Dict[str, Union[int, str]]:
         r"""
-        Additional items to be displayed in the progress bar.
+        Implement this to override the default items displayed in the progress bar.
+        By default it includes the average loss value, split index of BPTT (if used)
+        and the version of the experiment when using a logger.
+
+        .. code-block::
+
+            Epoch 1:   4%|▎         | 40/1095 [00:03<01:37, 10.84it/s, loss=4.501, v_num=10]
+
+        Here is an example how to override the defaults:
+
+        .. code-block:: python
+
+            def get_progress_bar_dict(self):
+                # don't show the version number
+                items = super().get_progress_bar_dict()
+                items.pop("v_num", None)
+                return items
 
         Return:
             Dictionary with the items to be displayed in the progress bar.
@@ -1572,7 +1587,10 @@ class LightningModule(ABC, DeviceDtypeModuleMixin, GradInformation, ModelIO, Mod
             tqdm_dict['split_idx'] = self.trainer.split_idx
 
         if self.trainer.logger is not None and self.trainer.logger.version is not None:
-            tqdm_dict['v_num'] = self.trainer.logger.version
+            version = self.trainer.logger.version
+            # show last 4 places of long version strings
+            version = version[-4:] if isinstance(version, str) else version
+            tqdm_dict['v_num'] = version
 
         return tqdm_dict