fix download.py windows compatible (#15)

ppdet/utils/download.py

@@ -154,7 +154,7 @@ def create_voc_list(data_dir, devkit_subdir='VOCdevkit'):
 
 def map_path(url, root_dir):
     # parse path after download to decompress under root_dir
-    fname = url.split('/')[-1]
+    fname = osp.split(url)[-1]
     zip_formats = ['.zip', '.tar', '.gz']
     fpath = fname
     for zip_format in zip_formats:
@@ -186,7 +186,7 @@ def get_path(url, root_dir, md5sum=None, check_exist=True):
     }
     for k, v in decompress_name_map.items():
         if fullpath.find(k) >= 0:
-            fullpath = '/'.join(fullpath.split('/')[:-1] + [v])
+            fullpath = osp.join(osp.split(fullpath)[0], v)
 
     exist_flag = False
     if osp.exists(fullpath) and check_exist:
@@ -247,7 +247,7 @@ def _download(url, path, md5sum=None):
     if not osp.exists(path):
         os.makedirs(path)
 
-    fname = url.split('/')[-1]
+    fname = osp.split(url)[-1]
     fullname = osp.join(path, fname)
     retry_cnt = 0
 
@@ -314,7 +314,7 @@ def _decompress(fname):
     # decompress to fpath_tmp directory firstly, if decompress
     # successed, move decompress files to fpath and delete
     # fpath_tmp and remove download compress file.
-    fpath = '/'.join(fname.split('/')[:-1])
+    fpath = osp.split(fname)[0]
     fpath_tmp = osp.join(fpath, 'tmp')
     if osp.isdir(fpath_tmp):
         shutil.rmtree(fpath_tmp)