Fix mypy errors attributed to `pytorch_lightning.loggers.base.py` (#13494)

Co-authored-by: Rohit Gupta <rohitgr1998@gmail.com>
Co-authored-by: Carlos Mocholí <carlossmocholi@gmail.com>

pyproject.toml

@@ -59,7 +59,6 @@ module = [
     "pytorch_lightning.demos.boring_classes",
     "pytorch_lightning.demos.mnist_datamodule",
     "pytorch_lightning.distributed.dist",
-    "pytorch_lightning.loggers.base",
     "pytorch_lightning.loggers.comet",
     "pytorch_lightning.loggers.mlflow",
     "pytorch_lightning.loggers.neptune",

src/pytorch_lightning/loggers/base.py

@@ -12,16 +12,20 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from typing import Callable, Dict, Mapping, Optional, Sequence
+
+import numpy as np
+
 import pytorch_lightning.loggers.logger as logger
 from pytorch_lightning.utilities.warnings import rank_zero_deprecation
 
 
-def rank_zero_experiment(*args, **kwargs) -> None:  # type: ignore[no-untyped-def]
+def rank_zero_experiment(fn: Callable) -> Callable:
     rank_zero_deprecation(
         "The `pytorch_lightning.loggers.base.rank_zero_experiment` is deprecated in v1.7"
         " and will be removed in v1.9. Please use `pytorch_lightning.loggers.logger.rank_zero_experiment` instead."
     )
-    return logger.rank_zero_experiment(*args, **kwargs)
+    return logger.rank_zero_experiment(fn)
 
 
 class LightningLoggerBase(logger.Logger):
@@ -77,9 +81,13 @@ class DummyLogger(logger.DummyLogger):
         super().__init__(*args, **kwargs)
 
 
-def merge_dicts(*args, **kwargs) -> None:  # type: ignore[no-untyped-def]
+def merge_dicts(
+    dicts: Sequence[Mapping],
+    agg_key_funcs: Optional[Mapping] = None,
+    default_func: Callable[[Sequence[float]], float] = np.mean,
+) -> Dict:
     rank_zero_deprecation(
         "The `pytorch_lightning.loggers.base.merge_dicts` is deprecated in v1.7"
         " and will be removed in v1.9. Please use `pytorch_lightning.loggers.logger.merge_dicts` instead."
     )
-    return logger.merge_dicts(*args, **kwargs)
+    return logger.merge_dicts(dicts=dicts, agg_key_funcs=agg_key_funcs, default_func=default_func)

src/pytorch_lightning/loggers/logger.py

@@ -38,13 +38,13 @@ def rank_zero_experiment(fn: Callable) -> Callable:
     def experiment(self) -> Union[Any, DummyExperiment]:  # type: ignore[no-untyped-def]
         """
         Note:
-            `self` is a custom logger instance. The loggers typical wrap an `experiment` method
-            with a @rank_zero_experiment decorator. An exception being `loggers.neptune` wraps
-            `experiment` and `run` with rank_zero_experiment.
+            ``self`` is a custom logger instance. The loggers typically wrap an ``experiment`` method
+            with a ``@rank_zero_experiment`` decorator. An exception is that ``loggers.neptune`` wraps
+            ``experiment`` and ``run`` with rank_zero_experiment.
 
-            Union[Any, DummyExperiment] is used because the wrapped hooks have several returns
-            types that are specific to the custom logger. The return type can be considered as
-            Union[return type of logger.experiment, DummyExperiment]
+            ``Union[Any, DummyExperiment]`` is used because the wrapped hooks have several return
+            types that are specific to the custom logger. The return type here can be considered as
+            ``Union[return type of logger.experiment, DummyExperiment]``.
         """
 
         @rank_zero_only