diff --git a/_sidebar.md b/_sidebar.md
index e2fa30e..7693cac 100644
--- a/_sidebar.md
+++ b/_sidebar.md
@@ -9,8 +9,8 @@
     - [第一个 Hello World 程序](docs/course/foundation/04_hello_world.md)
     - [语言基础](docs/course/foundation/05_language_fundamentals.md)   
 
-- 其他小工具
-    - [JWT](jwt/README.md)
+- 附录索引
+    - [Python 用例索引](docs/appendix/01_use_cases.md)
     - [MessagePack](message-pack/index.md)
     - [Protocol Buffers](protocol-buffers/index.md)
 
diff --git a/tests/FileWith.py b/tests/FileWith.py
index b989bb5..221189c 100644
--- a/tests/FileWith.py
+++ b/tests/FileWith.py
@@ -3,7 +3,10 @@
 
 import json
 
+import ruamel.yaml as yaml
+
 json_filename = 'resources/honeymoose_test.json'
+yaml_filename = 'resources/honeymoose_test.yaml'
 
 # Read and process JSON
 with open(json_filename) as json_file:
@@ -15,3 +18,7 @@ with open(json_filename) as json_file:
         print(str(label_id))
 
 print(json_file.closed)
+
+# Using with write to YAML
+with open(yaml_filename, 'w') as yaml_file:
+    yaml.dump(data, yaml_file, allow_unicode=True)
diff --git a/tests/Json2Yaml.py b/tests/Json2Yaml.py
index b16b4a7..b13090a 100644
--- a/tests/Json2Yaml.py
+++ b/tests/Json2Yaml.py
@@ -2,6 +2,7 @@
 # Author - HoneyMoose (https://www.ossez.com)
 
 import json
+
 import ruamel.yaml as yaml
 
 json_filename = 'resources/black_rock_test.json'
@@ -18,6 +19,5 @@ with open(json_filename) as json_file:
 json_file.close()
 
 # Write to YAML
-yaml_file = open(yaml_filename, 'w+')
-yaml.dump(data, yaml_file, allow_unicode=True)
-yaml_file.close()
+with open(yaml_filename, 'w') as yaml_file:
+    yaml.dump(data, yaml_file, allow_unicode=True)