Improve error handling for action parsing

code/chapter1/FirstAgentTest.ipynb

@@ -315,8 +315,11 @@
     "        # 解析行动\n",
     "        action_match = re.search(r\"Action: (.*)\", llm_output, re.DOTALL)\n",
     "        if not action_match:\n",
-    "            print(\"❌ 解析错误：模型输出中未找到 Action。\")\n",
-    "            break\n",
+    "            observation = \"错误: 未能解析到 Action 字段。请确保你的回复严格遵循 'Thought: ... Action: ...' 的格式。\"\n",
+    "            observation_str = f\"Observation: {observation}\"\n",
+    "            print(f\"{observation_str}\\n\" + \"=\"*40)\n",
+    "            assistant.prompt_history.append(observation_str)\n",
+    "            continue\n",
     "            \n",
     "        action_str = action_match.group(1).strip()\n",
     "        tool_name, kwargs = parse_action(action_str)\n",