misc. docstring and type hint fixes [skip ci]

rastervision_pytorch_learner/rastervision/pytorch_learner/learner_config.py

@@ -727,9 +727,20 @@ def get_bbox_params(self) -> Optional[A.BboxParams]:
     def get_data_transforms(self) -> Tuple[A.BasicTransform, A.BasicTransform]:
         """Get albumentations transform objects for data augmentation.
 
+        Returns a 2-tuple of a "base" transform and an augmentation transform.
+        The base transform comprises a resize transform based on img_sz
+        followed by the transform specified in base_transform. The augmentation
+        transform comprises the base transform followed by either the transform
+        in aug_transform (if specified) or the transforms in the augmentors
+        field.
+
+        The augmentation transform is intended to be used for training data,
+        and the base transform for all other data where data augmentation is
+        not desirable, such as validation or prediction.
+
         Returns:
-           1st tuple arg: a transform that doesn't do any data augmentation
-           2nd tuple arg: a transform with data augmentation
+            Tuple[A.BasicTransform, A.BasicTransform]: base transform and
+                augmentation transform.
         """
         bbox_params = self.get_bbox_params()
         base_tfs = [A.Resize(self.img_sz, self.img_sz)]
@@ -1013,17 +1024,20 @@ def get_data_dirs(self, uri: Union[str, List[str]],
         (optinally) "test" subdirectories.
 
         Args:
-            uri (Union[str, List[str]]): a URI or a list of URIs of one of the
+            uri (Union[str, List[str]]): A URI or a list of URIs of one of the
                 following:
 
                 (1) a URI of a directory containing "train", "valid", and
                     (optinally) "test" subdirectories
                 (2) a URI of a zip file containing (1)
                 (3) a list of (2)
                 (4) a URI of a directory containing zip files containing (1)
+            unzip_dir (str): Directory where zip files will be extrated to, if
+                needed.
 
         Returns:
-            paths to directories that each contain contents of one zip file
+            List[str]: Paths to directories that each contain contents of one
+                zip file.
         """
 
         def is_data_dir(uri: str) -> bool:
@@ -1066,11 +1080,12 @@ def unzip_data(self, zip_uris: List[str], unzip_dir: str) -> List[str]:
         """Unzip dataset zip files.
 
         Args:
-            zip_uris (List[str]): a list of URIs of zip files:
-            unzip_dir (str): directory where zip files will be extrated to.
+            zip_uris (List[str]): A list of URIs of zip files:
+            unzip_dir (str): Directory where zip files will be extrated to.
 
         Returns:
-            paths to directories that each contain contents of one zip file
+            List[str]: Paths to directories that each contain contents of one
+                zip file.
         """
         data_dirs = []
 
@@ -1413,7 +1428,7 @@ def build(self,
               model_weights_path: Optional[str] = None,
               model_def_path: Optional[str] = None,
               loss_def_path: Optional[str] = None,
-              training=True) -> 'Learner':
+              training: bool = True) -> 'Learner':
         """Returns a Learner instantiated using this Config.
 
         Args: