| from langchain_core.output_parsers import StrOutputParser |
| from langchain_core.prompts import ChatPromptTemplate |
| from langchain_core.runnables import RunnablePassthrough |
| from langchain_community.chat_models import ChatAnthropic |
| from langchain_community.chat_models import ChatOpenAI |
| |
| prompt = ChatPromptTemplate.from_template( |
| "Tell me a short joke about {topic}") |
| output_parser = StrOutputParser() |
| anthropic = ChatAnthropic(model="claude-2") |
| anthropic_chain = ( |
| {"topic": RunnablePassthrough()} |
| | prompt |
| | anthropic |
| | output_parser |
| ) |
| model = ChatOpenAI(model="gpt-3.5-turbo") |
| chain = ( |
| {"topic": RunnablePassthrough()} |
| | prompt |
| | model |
| | output_parser |
| ) |
| |
| fallback_chain = chain.with_fallbacks([anthropic_chain]) |
| |
| if __name__ == "__main__": |
| print(fallback_chain.invoke("ice cream")) |
