fix dy-load bug, test=develop

python/paddle/fluid/dygraph/checkpoint.py

@@ -134,14 +134,19 @@ def _save_var_to_file(stat_dict, file_dir, file_name):
 
 def _load_var_from_file(file_dir):
     def walk_filename(file_dir):
+        base_path = os.path.join(file_dir)
         var_name_list = []
-        if os.path.exists(file_dir) and os.path.exists(os.path.join(file_dir)):
-            base_path = os.path.join(file_dir)
-            for dirpath, dirnames, filenames in os.walk(os.path.join(file_dir)):
-                pt = dirpath.replace(base_path, "", 1)[1:]
+        if os.path.exists(base_path):
+            for dirpath, dirnames, filenames in os.walk(base_path):
+                pt = dirpath.replace(base_path, "", 1)
+                if pt.startswith("/") or pt.startswith("\\"):
+                    pt = pt[1:]
                 for fth_name in filenames:
                     if fth_name[0] != '.':
-                        var_name_list.append(os.path.join(pt, fth_name))
+                        name_path = os.path.join(pt, fth_name)
+                        if "\\" in name_path:
+                            name_path = name_path.replace("\\", "/")
+                        var_name_list.append(name_path)
 
         return var_name_list