fixed odd orders

src/tree.py

@@ -107,17 +107,6 @@ class TreeWalker:
                     full_path = os.path.join(chapter_path, f"{index + 1}.{section_title}")
                     if os.path.isdir(full_path):
                         self.ensure_exercises(full_path)
-                        # TODO 四级知识点的处理仅为 Java 技能树的临时处理而设定，未来java技能树上线前会删掉这部分代码，将四级节点
-                        # 合并到三级节点
-                        for idx, [num, sub_section_title] in self.sort_dir_list([p for p in os.listdir(full_path)
-                                                                                 if os.path.isdir(os.path.join(full_path, p))]):
-                            order = idx + 1
-                            ensure_path = os.path.join(full_path, f"{order}.{sub_section_title}")
-                            forth_full_path = os.path.join(full_path, f"{num}.{sub_section_title}")
-                            if ensure_path != forth_full_path:
-                                os.rename(forth_full_path, ensure_path)
-                            if os.path.isdir(ensure_path):
-                                self.ensure_exercises(forth_full_path)
 
         tree_path = os.path.join(self.root, "tree.json")
         dump_json(tree_path, self.tree, exist_ok=True, override=True)
@@ -310,6 +299,6 @@ class TreeWalker:
             full_name = os.path.join(section_path, e)
             logger.info(full_name)
             exercise = load_json(full_name)
-            if "exercise_id" not in exercise:
+            if not exercise.get("exercise_id"):
                 exercise["exercise_id"] = uuid.uuid4().hex
                 dump_json(full_name, exercise, exist_ok=True, override=True)