LangChain setup for running locally

Setup

Note

You can skip this page if you are interested in Colab notebooks only.

These are the instructions for local setup of the LangChain-specific Python environment. A prerequisite is the general setup for running locally.

You should have a copy of this repository from the general local-run setup already. Go to the docs/frameworks/langchain subdirectory.

Create a Python 3.8+ virtual environment, activate it and install the required dependencies with:

pip install -r requirements_langchain.txt

Info

We are still in the process of getting all Cassandra components in the distributed LangChain: for this reason, until this is completed, the current requirements file temporarily installs LangChain from a fork we maintain.

Launch

Make sure you are in docs/frameworks/langchain and the virtual environment is active.

Source the API Key configuration with

. ../../../.api_keys

Now fire up Jupyter with:

jupyter notebook

and wait for a browser window to open with the notebooks in this directory, ready to run.

Database choice

The code looks for an Astra DB instance by default (as defined in the .env file at the root of this repo).

If you have a Cassandra cluster and want to use it instead, all you need is to find the notebook cell where the two calls getCQLSession and getCQLKeyspace take place: you can switch to a Cassandra cluster by changing the value of the variable cqlMode therein from astra_db to local. See the "Further reading" section for more on using a local Cassandra.