Files
2026-07-13 13:22:34 +08:00

65 lines
2.1 KiB
Python

# This example demonstrates defining a model directly from code.
# This feature allows for defining model logic within a python script, module, or notebook that is stored
# directly as serialized code, as opposed to object serialization that would otherwise occur when saving
# or logging a model object.
# This script defines the model's logic and specifies which class within the file contains the model code.
# The companion example to this, chain_as_code_driver.py, is the driver code that performs the logging and
# loading of this model definition.
import os
from operator import itemgetter
from langchain_core.output_parsers import StrOutputParser
from langchain_core.prompts import PromptTemplate
from langchain_core.runnables import RunnableLambda
from langchain_openai import OpenAI
import mlflow
mlflow.langchain.autolog()
assert "OPENAI_API_KEY" in os.environ, "Please set the OPENAI_API_KEY environment variable."
# Return the string contents of the most recent message from the user
def extract_user_query_string(chat_messages_array):
return chat_messages_array[-1]["content"]
# Return the chat history, which is is everything before the last question
def extract_chat_history(chat_messages_array):
return chat_messages_array[:-1]
prompt = PromptTemplate(
template="You are a hello world bot. Respond with a reply to the user's question that is fun and interesting to the user. User's question: {question}",
input_variables=["question"],
)
model = OpenAI(temperature=0.9)
chain = (
{
"question": itemgetter("messages") | RunnableLambda(extract_user_query_string),
"chat_history": itemgetter("messages") | RunnableLambda(extract_chat_history),
}
| prompt
| model
| StrOutputParser()
)
question = {
"messages": [
{
"role": "user",
"content": "what is rag?",
},
]
}
chain.invoke(question)
# IMPORTANT: The model code needs to call `mlflow.models.set_model()` to set the model,
# which will be loaded back using `mlflow.langchain.load_model` for inference.
mlflow.models.set_model(model=chain)