Fix typo and import error in multiple files (#4992)

* Fix typo

* Fix comments

configs/_base_/datasets/cityscapes_detection.py

@@ -1,3 +1,4 @@
+# dataset settings
 dataset_type = 'CityscapesDataset'
 data_root = 'data/cityscapes/'
 img_norm_cfg = dict(

configs/_base_/datasets/cityscapes_instance.py

@@ -1,3 +1,4 @@
+# dataset settings
 dataset_type = 'CityscapesDataset'
 data_root = 'data/cityscapes/'
 img_norm_cfg = dict(

configs/_base_/datasets/coco_detection.py

@@ -1,3 +1,4 @@
+# dataset settings
 dataset_type = 'CocoDataset'
 data_root = 'data/coco/'
 img_norm_cfg = dict(

configs/_base_/datasets/coco_instance.py

@@ -1,3 +1,4 @@
+# dataset settings
 dataset_type = 'CocoDataset'
 data_root = 'data/coco/'
 img_norm_cfg = dict(

configs/_base_/datasets/coco_instance_semantic.py

@@ -1,3 +1,4 @@
+# dataset settings
 dataset_type = 'CocoDataset'
 data_root = 'data/coco/'
 img_norm_cfg = dict(

configs/_base_/datasets/lvis_v0.5_instance.py

@@ -1,3 +1,4 @@
+# dataset settings
 _base_ = 'coco_instance.py'
 dataset_type = 'LVISV05Dataset'
 data_root = 'data/lvis_v0.5/'

configs/_base_/datasets/lvis_v1_instance.py

@@ -1,3 +1,4 @@
+# dataset settings
 _base_ = 'coco_instance.py'
 dataset_type = 'LVISV1Dataset'
 data_root = 'data/lvis_v1/'

configs/_base_/models/faster_rcnn_r50_fpn.py

@@ -1,3 +1,4 @@
+# model settings
 model = dict(
     type='FasterRCNN',
     pretrained='torchvision://resnet50',

configs/_base_/models/retinanet_r50_fpn.py

@@ -41,7 +41,7 @@ model = dict(
             alpha=0.25,
             loss_weight=1.0),
         loss_bbox=dict(type='L1Loss', loss_weight=1.0)),
-    # training and testing settings
+    # model training and testing settings
     train_cfg=dict(
         assigner=dict(
             type='MaxIoUAssigner',

configs/_base_/models/rpn_r50_fpn.py

@@ -1,5 +1,4 @@
 # model settings
-
 model = dict(
     type='RPN',
     pretrained='torchvision://resnet50',

configs/_base_/models/ssd300.py

@@ -28,6 +28,7 @@ model = dict(
             type='DeltaXYWHBBoxCoder',
             target_means=[.0, .0, .0, .0],
             target_stds=[0.1, 0.1, 0.2, 0.2])),
+    # model training and testing settings
     train_cfg=dict(
         assigner=dict(
             type='MaxIoUAssigner',

mmdet/models/roi_heads/roi_extractors/__init__.py

@@ -1,7 +1,5 @@
+from .base_roi_extractor import BaseRoIExtractor
 from .generic_roi_extractor import GenericRoIExtractor
 from .single_level_roi_extractor import SingleRoIExtractor
 
-__all__ = [
-    'SingleRoIExtractor',
-    'GenericRoIExtractor',
-]
+__all__ = ['BaseRoIExtractor', 'SingleRoIExtractor', 'GenericRoIExtractor']