update config.py

npu_mnist_example/config.py

@@ -20,6 +20,9 @@ class Config:
     def __init__(self, **entries):
         self.__dict__.update(entries)
 
+    def __getitem__(self, item):
+        return self.__dict__[item]
+
 # 定义配置信息
 mnist_cfg = Config(
     num_classes=10,