使用 LangChain 设计 Agentic 系统
Dilini K. Sumanapala, PhD
Founder & AI Engineer, Genverv, Ltd.


Agent: The 5th of November is famous for the Gunpowder treason and
plot...
string == string[::-1] Agent: Yes, "madam" is a palindrome...
# 使用装饰器标注工具并将输入格式设为字符串 @tooldef date_checker(date: str) -> str:"""为任意格式的日期提供重要历史事件列表。"""try: # 调用 LLM 解读日期并生成历史事件 answer = llm.invoke(f"List important historical events that occurred on {date}.")# 返回响应 return answer.content# 为检索错误设置异常处理 except Exception as e: return f"Error retrieving events: {str(e)}"
@tool# 将输入格式设为字符串 def check_palindrome(text: str):"""检查单词或短语是否为回文。"""# 去除非字母数字字符并转为小写 cleaned = ''.join(char.lower() for char in text if char.isalnum())# 判断反转后是否与原文本相同 if cleaned == cleaned[::-1]: return f"The phrase or word '{text}' is a palindrome." else: return f"The phrase or word '{text}' is not a palindrome."
# 导入定义工具节点所需模块 from langgraph.prebuilt import ToolNode# 工具列表 tools = [wikipedia_tool, date_checker, check_palindrome]# 将工具传给 ToolNode() tool_node = ToolNode(tools)# 绑定工具到 LLM model_with_tools = llm.bind_tools(tools)
使用 LangChain 设计 Agentic 系统