cannot import name 'LangchainEmbedding' from 'llama_index'

Question

I'm trying to build a simple RAG, and I'm stuck at this code:

from langchain.embeddings.huggingface import HuggingFaceEmbeddings
from llama_index import LangchainEmbedding, ServiceContext

embed_model = LangchainEmbedding(
  HuggingFaceEmbeddings(model_name="thenlper/gte-large")
)
service_context = ServiceContext.from_defaults(
    chunk_size=256,
    llm=llm,
    embed_model=embed_model
)
index = VectorStoreIndex.from_documents(documents, service_context=service_context)

where I get ImportError: cannot import name 'LangchainEmbedding' from 'llama_index' How can I solve? Is it related to the fact that I'm working on Colab?

Answer 1

Not

from llama_index import LangchainEmbedding

but

from llama_index.embeddings import LangchainEmbedding

(See source code for llama_index/embeddings/__ init__.py)

Answer 2

Now this is the right Answer, LangchainEmbedding replace with HuggingFaceEmbeddings. Now its working.

from langchain.embeddings import HuggingFaceEmbeddings
from llama_index import ServiceContext, set_global_service_context

embed_model = HuggingFaceEmbeddings(
    model_name="sentence-transformers/all-mpnet-base-v2"
)

Answer 3

For a problem with

from llama_index import LangchainEmbedding

or

from llama_index.embedings import LangchainEmbedding

It looks like the syntax has been updated yet again, see:

https://github.com/run-llama/llama_index/blob/main/llama_index/embeddings/__init__.py

As of 2023 Dec 7th, it says:

from llama_index.embeddings.langchain import LangchainEmbedding

Today that works...tomorrow...a brave new world.

Answer 4

With reference to above code. This is working exactly.

from langchain.embeddings.huggingface import HuggingFaceEmbeddings
from llama_index import ServiceContext, set_global_service_context

embed_model = HuggingFaceEmbeddings(
  model_name="thenlper/gte-large"
)