reformat checkpoint

mmcv/runner/checkpoint.py

+from importlib import import_module
+import pkgutil
 import os.path as osp
 import time
 from collections import OrderedDict
@@ -6,18 +8,14 @@ import mmcv
 import torch
 from torch.utils import model_zoo
 
+
 open_mmlab_model_urls = {
-    'vgg16_caffe':
-    'https://s3.ap-northeast-2.amazonaws.com/open-mmlab/pretrain/third_party/vgg16_caffe-292e1171.pth',
-    'resnet50_caffe':
-    'https://s3.ap-northeast-2.amazonaws.com/open-mmlab/pretrain/third_party/resnet50_caffe-788b5fa3.pth',
-    'resnet101_caffe':
-    'https://s3.ap-northeast-2.amazonaws.com/open-mmlab/pretrain/third_party/resnet101_caffe-3ad79236.pth',
-    'resnext101_32x4d':
-    'https://s3.ap-northeast-2.amazonaws.com/open-mmlab/pretrain/third_party/resnext101_32x4d-a5af3160.pth',
-    'resnext101_64x4d':
-    'https://s3.ap-northeast-2.amazonaws.com/open-mmlab/pretrain/third_party/resnext101_64x4d-ee2c6f71.pth'
-}
+    'vgg16_caffe': 'https://s3.ap-northeast-2.amazonaws.com/open-mmlab/pretrain/third_party/vgg16_caffe-292e1171.pth',
+    'resnet50_caffe': 'https://s3.ap-northeast-2.amazonaws.com/open-mmlab/pretrain/third_party/resnet50_caffe-788b5fa3.pth',
+    'resnet101_caffe': 'https://s3.ap-northeast-2.amazonaws.com/open-mmlab/pretrain/third_party/resnet101_caffe-3ad79236.pth',
+    'resnext101_32x4d': 'https://s3.ap-northeast-2.amazonaws.com/open-mmlab/pretrain/third_party/resnext101_32x4d-a5af3160.pth',
+    'resnext101_64x4d': 'https://s3.ap-northeast-2.amazonaws.com/open-mmlab/pretrain/third_party/resnext101_64x4d-ee2c6f71.pth'
+} # noqa: E501
 
 
 def load_state_dict(module, state_dict, strict=False, logger=None):
@@ -94,13 +92,11 @@ def load_checkpoint(model,
     # load checkpoint from modelzoo or file or url
     if filename.startswith('modelzoo://'):
         import torchvision
-        import pkgutil
-        import inspect
         model_urls = dict()
         for _, name, ispkg in pkgutil.walk_packages(
                 torchvision.models.__path__):
-            _zoo = getattr(torchvision.models, name)
-            if inspect.ismodule(_zoo):
+            if not ispkg:
+                _zoo = import_module('torchvision.models.{}'.format(name))
                 _urls = getattr(_zoo, 'model_urls')
                 model_urls.update(_urls)
         model_name = filename[11:]