Installation
pip install langchain
Install LangChain library
pip install langchain-openai
Install LangChain OpenAI integration
Basic LangChain Setup
from langchain.llms import OpenAI
Import OpenAI LLM
llm = OpenAI(openai_api_key='your-api-key')
Initialize OpenAI LLM
llm('your prompt here')
Generate simple completion
Chains
from langchain.chains import LLMChain
Import basic LLMChain
from langchain.prompts import PromptTemplate
Import PromptTemplate
chain = LLMChain(llm=llm, prompt=prompt)
Create a chain
chain.run(input_variables)
Execute a chain
Agents
from langchain.agents import initialize_agent, Tool
Import agent components
agent = initialize_agent(tools, llm, agent='zero-shot-react-description')
Create an agent
agent.run('your task here')
Run an agent
Memory
from langchain.memory import ConversationBufferMemory
Import conversation memory
memory = ConversationBufferMemory()
Initialize memory
chain = LLMChain(llm=llm, prompt=prompt, memory=memory)
Add memory to chain
Document Loading
from langchain.document_loaders import TextLoader
Import document loader
loader = TextLoader('path/to/file.txt')
Create a loader
documents = loader.load()
Load documents
Embeddings
from langchain.embeddings import OpenAIEmbeddings
Import embeddings
embeddings = OpenAIEmbeddings()
Initialize embeddings
vector = embeddings.embed_query('your text')
Create embedding for text
Vector Stores
from langchain.vectorstores import Chroma
Import vector store
db = Chroma.from_documents(documents, embeddings)
Create vector store from documents
docs = db.similarity_search('query')
Search for similar documents
Debugging
import langchain
Import LangChain
langchain.debug = True
Enable debug mode
langchain.verbose = True
Enable verbose mode