""" Slide 12: with_structured_output -- рекомендованный путь Section 1: LangChain 1.0 Source: slides/section1-chains/slide-12.js Сгенерировано автоматически из slide-NN.js / sectionN.pptx. Паттерн провайдера скопирован из bro-js/agents/teacher/assistant/src/angry_teacher/llm.py. Запуск: cd langchain-evolution-deck cp .env.example .env # заполни OPENAI_API_KEY python examples/slide-012/script.py """ import os from dotenv import load_dotenv from langchain_openai import ChatOpenAI load_dotenv() llm = ChatOpenAI( # model="openrouter/free", # model="qwen/qwen3.5-35b-a3b", model="openai/gpt-oss-20b", # model="nvidia/nemotron-3-nano", # model="qwen/qwen3.5-9b", base_url="https://llm.brojs.ru/v1", # base_url="https://api.minimax.io/v1", # base_url="http://0.0.0.0:8090/v1", # base_url="https://openrouter.ai/api/v1", # api_key=os.getenv("MINIMAX_API_KEY"), api_key=(os.getenv("OPENAI_API_KEY") or "").strip() or None, temperature=0.7, stream_usage=True, ) # === Code from slide 12 === from pydantic import BaseModel, Field from langchain.chat_models import init_chat_model class Weather(BaseModel): city: str = Field(description="City name") temperature_c: float = Field(description="Temperature in Celsius") conditions: str = Field(description="Weather summary") # Один вызов -- и модель возвращает типизированный Pydantic-объект model = init_chat_model("openai:gpt-4.1-mini") structured = model.with_structured_output(Weather) result: Weather = structured.invoke("Weather in Paris?") print(result.city, result.temperature_c, result.conditions) # method="json_mode" -- если провайдер не поддерживает tool calling # structured_json = model.with_structured_output(Weather, method="json_mode")