Getting Started with LangChain

Introduction

An introduction to how to use Langchain.

Basic writing with LCEL will be introduced.

The model used was gpt-3.5-turbo.

Reference Documents

Official Documents

https://python.langchain.com/docs/get_started/quickstart

LCEL

https://python.langchain.com/docs/expression_language/

Setup

Install

python -V
Python 3.11.6

pip install python-dotenv

pip install langchain
pip show langchain
Version: 0.1.9

pip install langchain-openai
pip show langchain-openai
Version: 0.0.7

pip install langchain-core
pip show langchain-core
Version: 0.1.27

Create File

Create a directory (e.g. test_langchain)

• /test_langchain/.env


• /test_langchain/test.py

ENV file

Set your OpenAI API Key.

OPENAI_API_KEY="***********"

Sample code

test.py …

basic core documents gpt gpt-3 gpt-3.5 gpt-3.5-turbo how to use langchain install introduction langchain openai pip python python 3 reference setup show turbo will writing