ImportError: Cannot import 'load_qa_chain' from langchain.chains.question_answering with Python 3.7.3 and langchain 0.0.27

[Ryan_Innovative]

I built a web application using Flask and everything worked perfectly on my local machine. However, when I tried to deploy it on my Linode server, I started getting import errors.

My local setup uses Python 3.10.6, but the server runs Python 3.7.3 with langchain version 0.0.27. Here are the imports I’m trying to use:

from flask import Flask, render_template, request
import openai
import pinecone
import json
from langchain.embeddings.openai import OpenAIEmbeddings
from langchain.chains.question_answering import load_qa_chain
from langchain.llms import OpenAI
from langchain.vectorstores import Pinecone
import os

When I run my application, I get this error: ModuleNotFoundError: No module named 'langchain.chains.question_answering'

I’ve already tried several troubleshooting steps including updating packages, recreating the virtual environment, and even setting up a completely new server instance. None of these attempts resolved the issue.

Has anyone encountered similar problems with older langchain versions? What would be the best approach to fix this import error?

[liamj]

Hit this exact issue last year deploying to an old Ubuntu box. Langchain 0.0.27 is ancient - the API was totally different back then. Don’t try making the old version work, just upgrade your server. Python 3.7.3 is dying soon anyway, so you’ve got multiple problems here. I used pyenv to get Python 3.10 running, then installed current langchain. Took 30 minutes but saved hours of debugging those constantly changing import paths. If you can’t upgrade right now, downgrade your local setup to match the server temporarily.

[Finn_Mystery]

This is a version mismatch issue. I hit the same problem with an old production server that was stuck on an older version. The langchain.chains.question_answering module got restructured big time between 0.0.27 and newer releases. For 0.0.27, try from langchain.chains import load_qa_chain instead of going through the question_answering submodule. The load_qa_chain function lived in the main chains module back then. If that doesn’t work, check the 0.0.27 docs or upgrade your server’s Python version so you can use a newer langchain that matches your local setup.