Remove useless pass and abc (Lightning-AI#11522)

pytorch_lightning/callbacks/base.py

@@ -12,11 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 r"""
-Abstract base class used to build new callbacks.
+Base class used to build new callbacks.
 
 """
 
-import abc
 from typing import Any, Dict, List, Optional, Type
 
 import torch
@@ -26,7 +25,7 @@
 from pytorch_lightning.utilities.types import STEP_OUTPUT
 
 
-class Callback(abc.ABC):
+class Callback:
     r"""
     Abstract base class used to build new callbacks.
 
@@ -62,15 +61,12 @@ def on_configure_sharded_model(self, trainer: "pl.Trainer", pl_module: "pl.Light
 
     def on_before_accelerator_backend_setup(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
         """Called before accelerator is being setup."""
-        pass
 
     def setup(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule", stage: Optional[str] = None) -> None:
         """Called when fit, validate, test, predict, or tune begins."""
-        pass
 
     def teardown(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule", stage: Optional[str] = None) -> None:
         """Called when fit, validate, test, predict, or tune ends."""
-        pass
 
     def on_init_start(self, trainer: "pl.Trainer") -> None:
         r"""
@@ -79,7 +75,6 @@ def on_init_start(self, trainer: "pl.Trainer") -> None:
 
         Called when the trainer initialization begins, model has not yet been set.
         """
-        pass
 
     def on_init_end(self, trainer: "pl.Trainer") -> None:
         r"""
@@ -88,23 +83,18 @@ def on_init_end(self, trainer: "pl.Trainer") -> None:
 
         Called when the trainer initialization ends, model has not yet been set.
         """
-        pass
 
     def on_fit_start(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
         """Called when fit begins."""
-        pass
 
     def on_fit_end(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
         """Called when fit ends."""
-        pass
 
     def on_sanity_check_start(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
         """Called when the validation sanity check starts."""
-        pass
 
     def on_sanity_check_end(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
         """Called when the validation sanity check ends."""
-        pass
 
     def on_train_batch_start(
         self,
@@ -115,7 +105,6 @@ def on_train_batch_start(
         unused: int = 0,
     ) -> None:
         """Called when the train batch begins."""
-        pass
 
     def on_train_batch_end(
         self,
@@ -127,11 +116,9 @@ def on_train_batch_end(
         unused: int = 0,
     ) -> None:
         """Called when the train batch ends."""
-        pass
 
     def on_train_epoch_start(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
         """Called when the train epoch begins."""
-        pass
 
     def on_train_epoch_end(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
         """Called when the train epoch ends.
@@ -141,53 +128,41 @@ def on_train_epoch_end(self, trainer: "pl.Trainer", pl_module: "pl.LightningModu
         1. Implement `training_epoch_end` in the `LightningModule` and access outputs via the module OR
         2. Cache data across train batch hooks inside the callback implementation to post-process in this hook.
         """
-        pass
 
     def on_validation_epoch_start(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
         """Called when the val epoch begins."""
-        pass
 
     def on_validation_epoch_end(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
         """Called when the val epoch ends."""
-        pass
 
     def on_test_epoch_start(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
         """Called when the test epoch begins."""
-        pass
 
     def on_test_epoch_end(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
         """Called when the test epoch ends."""
-        pass
 
     def on_predict_epoch_start(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
         """Called when the predict epoch begins."""
-        pass
 
     def on_predict_epoch_end(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule", outputs: List[Any]) -> None:
         """Called when the predict epoch ends."""
-        pass
 
     def on_epoch_start(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
         """Called when either of train/val/test epoch begins."""
-        pass
 
     def on_epoch_end(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
         """Called when either of train/val/test epoch ends."""
-        pass
 
     def on_batch_start(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
         """Called when the training batch begins."""
-        pass
 
     def on_batch_end(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
         """Called when the training batch ends."""
-        pass
 
     def on_validation_batch_start(
         self, trainer: "pl.Trainer", pl_module: "pl.LightningModule", batch: Any, batch_idx: int, dataloader_idx: int
     ) -> None:
         """Called when the validation batch begins."""
-        pass
 
     def on_validation_batch_end(
         self,
@@ -199,13 +174,11 @@ def on_validation_batch_end(
         dataloader_idx: int,
     ) -> None:
         """Called when the validation batch ends."""
-        pass
 
     def on_test_batch_start(
         self, trainer: "pl.Trainer", pl_module: "pl.LightningModule", batch: Any, batch_idx: int, dataloader_idx: int
     ) -> None:
         """Called when the test batch begins."""
-        pass
 
     def on_test_batch_end(
         self,
@@ -217,13 +190,11 @@ def on_test_batch_end(
         dataloader_idx: int,
     ) -> None:
         """Called when the test batch ends."""
-        pass
 
     def on_predict_batch_start(
         self, trainer: "pl.Trainer", pl_module: "pl.LightningModule", batch: Any, batch_idx: int, dataloader_idx: int
     ) -> None:
         """Called when the predict batch begins."""
-        pass
 
     def on_predict_batch_end(
         self,
@@ -235,47 +206,36 @@ def on_predict_batch_end(
         dataloader_idx: int,
     ) -> None:
         """Called when the predict batch ends."""
-        pass
 
     def on_train_start(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
         """Called when the train begins."""
-        pass
 
     def on_train_end(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
         """Called when the train ends."""
-        pass
 
     def on_pretrain_routine_start(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
         """Called when the pretrain routine begins."""
-        pass
 
     def on_pretrain_routine_end(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
         """Called when the pretrain routine ends."""
-        pass
 
     def on_validation_start(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
         """Called when the validation loop begins."""
-        pass
 
     def on_validation_end(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
         """Called when the validation loop ends."""
-        pass
 
     def on_test_start(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
         """Called when the test begins."""
-        pass
 
     def on_test_end(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
         """Called when the test ends."""
-        pass
 
     def on_predict_start(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
         """Called when the predict begins."""
-        pass
 
     def on_predict_end(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
         """Called when predict ends."""
-        pass
 
     def on_keyboard_interrupt(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
         r"""
@@ -284,11 +244,9 @@ def on_keyboard_interrupt(self, trainer: "pl.Trainer", pl_module: "pl.LightningM
 
         Called when any trainer execution is interrupted by KeyboardInterrupt.
         """
-        pass
 
     def on_exception(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule", exception: BaseException) -> None:
         """Called when any trainer execution is interrupted by an exception."""
-        pass
 
     def on_save_checkpoint(
         self, trainer: "pl.Trainer", pl_module: "pl.LightningModule", checkpoint: Dict[str, Any]
@@ -303,7 +261,6 @@ def on_save_checkpoint(
         Returns:
             The callback state.
         """
-        pass
 
     def on_load_checkpoint(
         self, trainer: "pl.Trainer", pl_module: "pl.LightningModule", callback_state: Dict[str, Any]
@@ -320,22 +277,17 @@ def on_load_checkpoint(
             If your ``on_load_checkpoint`` hook behavior doesn't rely on a state,
             you will still need to override ``on_save_checkpoint`` to return a ``dummy state``.
         """
-        pass
 
     def on_before_backward(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule", loss: torch.Tensor) -> None:
         """Called before ``loss.backward()``."""
-        pass
 
     def on_after_backward(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule") -> None:
         """Called after ``loss.backward()`` and before optimizers are stepped."""
-        pass
 
     def on_before_optimizer_step(
         self, trainer: "pl.Trainer", pl_module: "pl.LightningModule", optimizer: Optimizer, opt_idx: int
     ) -> None:
         """Called before ``optimizer.step()``."""
-        pass
 
     def on_before_zero_grad(self, trainer: "pl.Trainer", pl_module: "pl.LightningModule", optimizer: Optimizer) -> None:
         """Called before ``optimizer.zero_grad()``."""
-        pass