I’m trying to use LangChain in my Python project. My current retriever.py contains:
from langchain.chains import RetrievalQA
But when I run my code, I get:
ImportError: cannot import name 'RetrievalQA' from 'langchain.chains'
My current environment:
Python 3.13.7
langchain version: 1.0.5
OS: Windows 11
In LangChain 1.x, the legacy RetrievalQA class is no longer exported from langchain.chains (API was reorganized). Your import works only on older 0.x versions.
You could Import the legacy class from its module path
from langchain.chains.retrieval_qa.base import RetrievalQA
(Works if the class still ships in your version, but it’s deprecated in favor of the functions above.)
Or you could try and Pin to a compatible older LangChain
pip install "langchain<0.1.0"
Then:
from langchain.chains import RetrievalQA
