# my_plan_solve_agent.py
"""重写的 Plan-and-Solve Agent - 分解规划与逐步执行"""
import ast
import re
from typing import Optional, Dict, List
from hello_agents import PlanAndSolveAgent, HelloAgentsLLM, Config, Message
from hello_agents.agents.plan_solve_agent import (
DEFAULT_PLANNER_PROMPT,
DEFAULT_EXECUTOR_PROMPT,
)
class MyPlanner:
"""规划器 - 将复杂问题分解为可执行步骤"""
def __init__(
self,
llm: HelloAgentsLLM,
prompt_template: Optional[str] = None,
system_prompt: Optional[str] = None,
):
self.llm = llm
self.prompt_template = prompt_template or DEFAULT_PLANNER_PROMPT
self.system_prompt = system_prompt
def plan(self, question: str, **kwargs) -> List[str]:
prompt = self.prompt_template.format(question=question)
print(f"prompt:{prompt}")
messages = self._build_messages(prompt)
print("--- 正在生成计划 ---")
response_text = self.llm.invoke(messages, **kwargs) or ""
print(f"✅ 计划已生成:\n{response_text}")
plan = self._parse_plan(response_text)
if not plan:
print("❌ 解析计划失败，无法提取有效步骤列表")
return plan
def _build_messages(self, prompt: str) -> list:
messages = []
if self.system_prompt:
messages.append({"role": "system", "content": self.system_prompt})
messages.append({"role": "user", "content": prompt})
return messages
def _parse_plan(self, response_text: str) -> List[str]:
"""从 LLM 响应中解析 Python 列表格式的计划"""
# 优先解析 ```python ... ``` 代码块
if "```python" in response_text:
try:
plan_str = response_text.split("```python")[1].split("```")[0].strip()
plan = ast.literal_eval(plan_str)
return plan if isinstance(plan, list) else []
except (ValueError, SyntaxError, IndexError) as e:
print(f"❌ 解析 python 代码块时出错: {e}")
# 回退：解析任意 ``` ... ``` 代码块
code_blocks = re.findall(r"```(?:python)?\s*([\s\S]*?)```", response_text)
for block in code_blocks:
try:
plan = ast.literal_eval(block.strip())
if isinstance(plan, list) and plan:
return plan
except (ValueError, SyntaxError):
continue
# 回退：匹配响应中的 [...] 列表
list_match = re.search(r"\[[\s\S]*?\]", response_text)
if list_match:
try:
plan = ast.literal_eval(list_match.group())
return plan if isinstance(plan, list) else []
except (ValueError, SyntaxError) as e:
print(f"❌ 解析列表字面量时出错: {e}")
print(f"原始响应: {response_text}")
return []
class MyExecutor:
"""执行器 - 按计划逐步执行"""
def __init__(
self,
llm: HelloAgentsLLM,
prompt_template: Optional[str] = None,
system_prompt: Optional[str] = None,
):
self.llm = llm
self.prompt_template = prompt_template or DEFAULT_EXECUTOR_PROMPT
self.system_prompt = system_prompt
def execute(self, question: str, plan: List[str], **kwargs) -> str:
history = ""
final_answer = ""
print("\n--- 正在执行计划 ---")
for i, step in enumerate(plan, 1):
print(f"\n-> 正在执行步骤 {i}/{len(plan)}: {step}")
prompt = self.prompt_template.format(
question=question,
plan=plan,
history=history if history else "无",
current_step=step,
)
messages = self._build_messages(prompt)
response_text = self.llm.invoke(messages, **kwargs) or ""
history += f"步骤 {i}: {step}\n结果: {response_text}\n\n"
final_answer = response_text
print(f"✅ 步骤 {i} 已完成，结果: {final_answer}")
return final_answer
def _build_messages(self, prompt: str) -> list:
messages = []
if self.system_prompt:
messages.append({"role": "system", "content": self.system_prompt})
messages.append({"role": "user", "content": prompt})
return messages
class MyPlanAndSolveAgent(PlanAndSolveAgent):
"""
重写的 Plan-and-Solve Agent
基于框架 PlanAndSolveAgent，实现「规划 → 逐步执行」流程
"""
def __init__(
self,
name: str,
llm: HelloAgentsLLM,
system_prompt: Optional[str] = None,
config: Optional[Config] = None,
custom_prompts: Optional[Dict[str, str]] = None,
):
super().__init__(
name=name,
llm=llm,
system_prompt=system_prompt,
config=config,
custom_prompts=custom_prompts,
)
planner_prompt = (custom_prompts or {}).get("planner")
executor_prompt = (custom_prompts or {}).get("executor")
self.planner = MyPlanner(llm, planner_prompt, system_prompt)
self.executor = MyExecutor(llm, executor_prompt, system_prompt)
prompt_type = "自定义" if custom_prompts else "默认"
print(f"✅ {name} 初始化完成，提示词: {prompt_type}")
def run(self, input_text: str, **kwargs) -> str:
"""运行 Plan-and-Solve Agent"""
print(f"\n🤖 {self.name} 开始处理问题: {input_text}")
plan = self.planner.plan(input_text, **kwargs)
if not plan:
final_answer = "无法生成有效的行动计划，任务终止。"
print(f"\n--- 任务终止 ---\n{final_answer}")
self.add_message(Message(input_text, "user"))
self.add_message(Message(final_answer, "assistant"))
return final_answer
final_answer = self.executor.execute(input_text, plan, **kwargs)
print(f"\n--- 任务完成 ---\n最终答案: {final_answer}")
self.add_message(Message(input_text, "user"))
self.add_message(Message(final_answer, "assistant"))
return final_answer