Remove the deprecated pytorch_lightning.callbacks.base module (#16319)

Author: carmocca

src/pytorch_lightning/CHANGELOG.md

@@ -146,6 +146,9 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 - Removed the deprecated `pytorch_lightning.core.lightning` module in favor of `pytorch_lightning.core.module` ([#16318](https://github.com/PyTorchLightning/pytorch-lightning/pull/16318))
 
 
+- Removed the deprecated `pytorch_lightning.callbacks.base` module in favor of `pytorch_lightning.callbacks.callback` ([#16319](https://github.com/PyTorchLightning/pytorch-lightning/pull/16319))
+
+
 - Removed the deprecated `Trainer.reset_train_val_dataloaders()` in favor of `Trainer.reset_{train,val}_dataloader` ([#16131](https://github.com/Lightning-AI/lightning/pull/16131))
 
 

src/pytorch_lightning/_graveyard/callbacks.py

@@ -11,12 +11,27 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-
+import sys
 from typing import Any
 
 from pytorch_lightning.callbacks import ModelCheckpoint
 
 
+def _patch_sys_modules() -> None:
+    # TODO: Remove in v2.0.0
+    self = sys.modules[__name__]
+    sys.modules["pytorch_lightning.callbacks.base"] = self
+
+
+class Callback:
+    # TODO: Remove in v2.0.0
+    def __init__(self, *_: Any, **__: Any) -> None:
+        raise NotImplementedError(
+            "Importing `pytorch_lightning.callbacks.base.Callback` was deprecated in v1.7.0 and removed as of"
+            " v1.9.0. Please use `from pytorch_lightning import Callback` instead"
+        )
+
+
 def _save_checkpoint(_: ModelCheckpoint, __: Any) -> None:
     # TODO: Remove in v2.0.0
     raise NotImplementedError(
@@ -25,5 +40,7 @@ def _save_checkpoint(_: ModelCheckpoint, __: Any) -> None:
     )
 
 
+_patch_sys_modules()
+
 # Methods
 ModelCheckpoint.save_checkpoint = _save_checkpoint

src/pytorch_lightning/callbacks/base.py

@@ -17,6 +17,13 @@
 from pytorch_lightning.callbacks import ModelCheckpoint
 
 
+def test_v2_0_0_moved_callback():
+    from pytorch_lightning.callbacks.base import Callback
+
+    with pytest.raises(NotImplementedError, match="base.Callback.*was deprecated in v1.7.0 and removed as of v1.9"):
+        Callback()
+
+
 def test_v2_0_0_deprecated_mc_save_checkpoint():
     mc = ModelCheckpoint()
     with pytest.raises(