LangChain Explained in 13 Minutes | QuickStart Tutorial for Beginners
Summary
TLDRLangChain是一个开源框架,它允许开发者将大型语言模型如GPT-4与外部计算和数据源结合使用。这个框架特别在2023年3月GPT-4发布后变得流行。LangChain通过将文档分割成小块并存储在向量数据库中,使得语言模型能够引用整个数据库中的数据。这样,用户可以构建既能够引用个人数据又能执行操作(如发送电子邮件)的应用程序。LangChain的核心概念包括LLM包装器、提示模板、索引、链和代理。它支持开发者通过编写代码来构建应用程序,这些应用程序能够动态地根据用户输入变化提示,并执行复杂的任务,如解析文本、执行相似性搜索和与外部API交互。
Takeaways
- 📚 **链 (LangChain) 是一个开源框架,允许开发者将大型语言模型(如 GPT-4)与外部计算和数据源结合使用。
- 🚀 链的流行度在 GPT-4 于 2023 年 3 月发布后迅速上升,特别是因为它能够处理大量数据和执行复杂任务。
- 🔗 链允许将大型语言模型连接到个人数据源,如书籍、PDF 文件、含有专有信息的数据库等。
- 📈 链通过将文档分割成小块并存储在向量数据库中,以嵌入(向量表示)的形式,帮助构建能够执行通用流程的语言模型应用程序。
- 🤖 链帮助构建的数据感知且能够执行操作的应用程序,可以用于个人助理、学习、编码、数据分析等多个领域。
- 🔑 链的主要价值主张可以概括为三个概念:LLM 包装器、提示模板、索引、链和代理。
- 🛠️ LLM 包装器允许连接到大型语言模型,提示模板避免了硬编码文本,索引用于提取信息,链用于组合多个组件解决特定任务。
- 🧲 链使用 Pinecone 作为向量存储,可以将文本分割成小块,并通过 OpenAI 的嵌入模型 Ada 将文本转换为向量表示。
- 🔍 在 Pinecone 中存储向量后,可以进行相似性搜索以获取问题的答案或提取所有相关块。
- 📝 链还允许使用 Python 代码解释器,使语言模型能够运行 Python 代码,执行如求解二次函数根等计算任务。
- 🌐 链框架不断更新,提供了模型或模型包装器、问题、链、嵌入和向量存储以及代理等元素的高层次概览。
- 📈 链的应用程序可以连接到公司数据,如客户数据、市场营销数据等,预示着数据分析和数据科学领域将取得指数级进步。
Q & A
什么是LangChain?
-LangChain是一个开源框架,允许开发者将大型语言模型(如GPT-4)与外部计算和数据源结合起来使用。它提供了Python和JavaScript(具体是TypeScript)的包。
LangChain为什么特别有用?
-LangChain允许将大型语言模型连接到个人数据源,如数据库,并且能够执行基于检索信息的操作,如发送电子邮件,这使得它在数据感知和执行操作方面非常有用。
LangChain如何与GPT-4等大型语言模型配合使用?
-通过将数据分割成小块并存储为向量(即嵌入),LangChain可以构建一个向量数据库,使用户能够通过相似性搜索检索相关信息,并将这些信息提供给语言模型以生成答案或执行操作。
LangChain的主要价值主张是什么?
-LangChain的主要价值主张可以概括为三个概念:LLM包装器(连接大型语言模型)、提示模板(避免硬编码文本)、索引(提取LLM的相关信息)、链(组合多个组件以解决特定任务)、代理(允许LLM与外部API交互)。
如何使用LangChain构建应用程序?
-使用LangChain构建应用程序通常遵循一个管道:用户提出问题,问题发送到语言模型,然后使用问题的向量表示在向量数据库中进行相似性搜索,检索相关信息并将其提供给语言模型,从而生成答案或执行操作。
LangChain中的“链”是什么?
-在LangChain中,链是将语言模型和提示模板结合起来的接口,它接受用户的输入并从语言模型输出答案,类似于一个复合函数,其中内部函数是提示模板,外部函数是语言模型。
如何使用LangChain处理和存储文本数据?
-首先,使用文本分割器将文本分割成小块,然后使用OpenAI的嵌入模型(如Ada)将文本转换为向量表示,并将这些向量存储在Pinecone这样的向量存储库中。
LangChain中的代理有什么作用?
-LangChain中的代理允许大型语言模型与外部API交互,执行如运行Python代码、查找二次函数的根等操作,这增加了应用程序的功能和灵活性。
LangChain如何帮助数据科学和数据分析?
-LangChain能够连接大型语言模型到现有的公司数据,如客户数据、市场数据等,这有助于在数据科学和数据分析领域实现指数级的进步。
LangChain的提示模板是如何工作的?
-提示模板允许将用户输入注入到一段文本中,然后格式化提示并将其提供给语言模型,使得提示可以动态地根据用户输入变化。
LangChain是否支持与第三方API的集成?
-是的,LangChain支持与第三方API的集成,例如通过代理功能允许语言模型执行调用外部服务的操作,如使用OpenAI的Python代码解释器。
Outlines
🚀 链式框架简介:AI与大型语言模型的结合
第一段主要介绍了Lang chain框架,这是一个开源的框架,允许开发者将大型语言模型如GPT-4与外部计算和数据源结合。框架支持Python和JavaScript(具体为TypeScript)。视频将深入探讨Python框架,解释其为何在GPT-4于2023年3月发布后变得流行。通过一个实际例子,说明了如何将大型语言模型连接到个人数据源,如书籍、PDF文件或包含专有信息的数据库。Lang chain通过将文档分割成小块并存储在向量数据库中,使得语言模型能够访问整个数据库的信息,而不仅仅是文本片段。此外,Lang chain还能帮助执行所需操作,如发送包含特定信息的电子邮件。
📚 Lang chain核心概念与应用实例
第二段深入探讨了Lang chain的核心概念,包括大型语言模型(LLM)封装器、提示模板、索引、链和代理。LLM封装器允许连接到GPT-4等大型语言模型。提示模板避免了硬编码文本,使得可以动态地将用户输入注入到文本中。索引用于从语言模型中提取相关信息。链能够将多个组件组合在一起,解决特定任务并构建完整的LLM应用程序。代理允许语言模型与外部API进行交互。视频还演示了如何使用Lang chain构建一个能够解释机器学习概念并将其简化为五岁儿童能理解的语言的链。此外,还介绍了如何将文本分割成块并存储为向量表示,以便在向量数据库中进行搜索和检索。
🧮 向量存储与代理:Lang chain的高级应用
第三段讨论了向量存储的概念,特别是如何使用Lang chain和Pinecone将文本块转换为向量表示并存储。这涉及到使用OpenAI的嵌入模型Ada来获取文本的向量表示。然后,这些向量被存储在Pinecone中,允许进行相似性搜索以检索相关信息。最后,视频简要介绍了Lang chain中的代理概念,展示了如何使用OpenAI语言模型运行Python代码,例如找到二次函数的根。视频以鼓励订阅和感谢观看结束,旨在为观众提供Lang chain核心概念的简要介绍。
Mindmap
Keywords
💡LangChain
💡大型语言模型(LLM)
💡向量数据库
💡嵌入(Embeddings)
💡Prompt Templates
💡链(Chains)
💡APIs
💡数据科学
💡个人助理
💡学习
💡Python 代理
Highlights
LangChain 是一个开源框架,允许开发者结合 AI 大型语言模型如 GPT-4 与外部计算和数据源。
LangChain 以 Python 或 JavaScript 包的形式提供,特别是 TypeScript。
GPT-4 的引入使得 LangChain 框架的受欢迎程度在 2023 年 3 月后急剧上升。
LangChain 允许将大型语言模型连接到个人数据源,如书籍、PDF 文件或包含专有信息的数据库。
通过将文档分割成小块并存储在向量数据库中,LangChain 可以构建遵循通用流程的语言模型应用程序。
LangChain 帮助构建的数据感知应用程序不仅可以引用我们自己的数据,还可以采取行动,而不仅仅是回答问题。
LangChain 的能力开启了无数实际用例,包括个人助理、学习新事物、编码、数据分析和数据科学。
LangChain 能够将大型语言模型连接到现有公司数据,如客户数据和市场营销数据,预示着数据分析和数据科学将取得指数级进步。
LangChain 的主要价值主张可以概括为三个概念:LLM 包装器、提示模板、索引、链和代理。
LLM 包装器允许连接到像 GPT-4 这样的大型语言模型,提示模板避免了硬编码文本的需要。
索引用于从 LLM 中提取相关信息,链允许组合多个组件来解决特定任务并构建整个 LLM 应用程序。
代理允许 LLM 与外部 API 交互,例如执行 Python 代码或与 OpenAI 的语言模型交互。
LangChain 通过编写代码来逐步解包每个元素,首先安装必要的 Python 库和环境文件。
LangChain 使用 Pinecone 作为向量存储,展示了如何将文本分割成小块并存储为向量表示。
LangChain 的文本分割器工具允许将文本分割成适合存储在向量存储中的小块。
通过 OpenAI 的嵌入模型 Ada,可以将文本转换为向量表示,进而存储在 Pinecone 中。
LangChain 允许进行相似性搜索以从向量数据库中提取相关信息。
LangChain 的 Python 代理执行器可以运行 Python 代码,扩展了语言模型的功能。
视频旨在简要介绍 LangChain 的核心概念,并提供深入理解的起点。
Transcripts
blank chain what is it why should you
use it and how does it work let's have a
look
Lang chain is an open source framework
that allows developers working with AI
to combine large language models like
gbt4 with external sources of
computation and data the framework is
currently offered as a python or a
JavaScript package typescript to be
specific in this video we're going to
start unpacking the python framework and
we're going to see why the popularity of
the framework is exploding right now
especially after the introduction of
gpt4 in March 2023 to understand what
need Lang chain fills let's have a look
at a practical example so by now we all
know that chat typically or tpt4 has an
impressive general knowledge we can ask
it about almost anything and we'll get a
pretty good answer
suppose you want to know something
specifically from your own data your own
document it could be a book a PDF file a
database with proprietary information
link chain allows you to connect a large
language model like dbt4 to your own
sources of data and we're not talking
about pasting a snippet of a text
document into the chativity prompt we're
talking about referencing an entire
database filled with your own data
and not only that once you get the
information you need you can have Lang
chain help you take the action you want
to take for instance send an email with
some specific information
and the way you do that is by taking the
document you want your language model to
reference and then you slice it up into
smaller chunks and you store those
chunks in a Victor database the chunks
are stored as embeddings meaning they
are vector representations of the text
this allows you to build language model
applications that follow a general
pipeline a user asks an initial question
this question is then sent to the
language model and a vector
representation of that question is used
to do a similarity search in the vector
database this allows us to fetch the
relevant chunks of information from the
vector database and feed that to the
language model as well
now the language model has both the
initial question and the relevant
information from the vector database and
is therefore capable of providing an
answer or take an action
a link chain helps build applications
that follow a pipeline like this and
these applications are both data aware
we can reference our own data in a
vector store and they are authentic they
can take actions and not only provide
answers to questions
and these two capabilities open up for
an infinite number of practical use
cases anything involving personal
assistance will be huge you can have a
large language model book flights
transfer money pay taxes now imagine the
implications for studying and learning
new things you can have a large language
model reference an entire syllabus and
help you learn the material as fast as
possible coding data analysis data
science is all going to be affected by
this
one of the applications that I'm most
excited about is the ability to connect
large language models to existing
company data such as customer data
marketing data and so on
I think we're going to see an
exponential progress in data analytics
and data science our ability to connect
the large language models to Advanced
apis such as metas API or Google's API
is really gonna gonna make things take
off
so the main value proposition of Lang
chain can be divided into three main
Concepts
we have the llm wrappers that allows us
to connect to large language models like
gbt4 or the ones from hugging face
prompt templates allows us to avoid
having to hard code text which is the
input to the llms
then we have indexes that allows us to
extract relevant information for the
llms the chains allows us to combine
multiple components together to solve a
specific task and build an entire llm
application
and finally we have the agents that
allow the llm to interact with external
apis
there's a lot to unpack in Lang chain
and new stuff is being added every day
but on a high level this is what the
framework looks like we have models or
wrappers around models we have problems
we have chains we have the embeddings
and Vector stores which are the indexes
and then we have the agents so what I'm
going to do now is I'm going to start
unpacking each of these elements by
writing code and in this video I'm going
to keep it high level just to get an
overview of the framework and a feel for
the different elements first thing we're
going to do is we're going to pip
install three libraries we're going to
need python.in to manage the environment
file with the passwords we're going to
install link chain and we're going to
install the Pinecone client Pinecone is
going to be the vector store we're going
to be using in this video in the
environment file we need the open AI API
key we need the pine cone environment
and we need the pine cone API key
foreign once you have signed up for a
Pinecone account it's free the API keys
and the environment name is easy to find
same thing is true for openai just go to
platform.orgmaili.com account slash API
keys
let's get started so when you have the
keys in an environment file all you have
to do is use node.n and find that in to
get the keys and now we're ready to go
so we're going to start off with the
llms or the wrappers around the llms
then I'm going to import the open AI
Rubber and I'm going to instantiate the
text DaVinci 003 completion model and
ask it to explain what a large language
model is and this is very similar to
when you call the open AI API directly
next we're going to move over to the
chat model so gbt 3.5 and gbt4 are chat
models
and in order to interact with the chat
model through link chain we're going to
import a schema consisting of three
parts an AI message a human message and
a system message
and then we're going to import chat open
AI the system message is what you use to
configure the system when you use a
model and the human message is the user
message
thank you
to use the chat model you combine the
system message and the human message in
a list and then you use that as an input
to the chat model
here I'm using GPT 3.5 turbo you could
have used gpt4 I'm not using that
because the open AI service is a little
bit Limited at the moment
so this works no problem let's move to
the next concept which is prompt
templates so prompts are what we are
going to send to our language model but
most of the time these problems are not
going to be static they're going to be
dynamic they're going to be used in an
application and to do that link chain
has something called prompt templates
and what that allows us to do is to take
a piece of text and inject a user input
into that text and we can then format
The Prompt with the user input and feed
that to the language model
so this is the most basic example but it
allows us to dynamically change the
prompt with the user input
the third concept we want to Overlook at
is the concept of a chain
a chain takes a language model and a
prompt template and combines them into
an interface that takes an input from
the user and outputs an answer from the
language model sort of like a composite
function where the inner function is the
prompt template and the outer function
is the language model
we can also build sequential chains
where we have one chain returning an
output and then a second chain taking
the output from the first chain as an
input
so here we have the first chain that
takes a machine learning concept and
gives us a brief explanation of that
concept the second chain then takes the
description of the first concept and
explains it to me like I'm five years
old
then we simply combine the two chains
the first chain called chain and then
the second chain called chain two into
an overall chain
and run that chain
and we see that the overall chain
returns both the first description of
the concept and the explain it to me
like I'm 5 explanation of the concept
all right let's move on to embeddings
and Vector stores but before we do that
let me just change the explainer to me
like I'm five prompt so that we get a
few more words
I'm gonna go with 500 Words
all right so this is a slightly longer
explanation for a five-year-old
now what I'm going to do is I'm going to
check this text and I'm going to split
it into chunks because we want to store
it in a vector store in Pinecone
and Lang chain has a text bitter tool
for that so I'm going to import
recursive character text splitter and
then I'm going to spit the text into
chunks
like we talked about in the beginning of
the video
we can extract the plain text of the
individual elements of the list with
page content
and what we want to do now is we want to
turn this into an embedding which is
just a vector representation of this
text and we can use open ai's embedding
model Ada
with all my eyes model we can call embed
query on the raw text that we just
extracted from the chunks of the
document and then we get the vector
representation of that text or the
embedding
now we're going to check the chunks of
the explanation document and we're going
to store the vector representations in
pine cone
so we'll import the pine cone python
client and we'll import pine cone from
Lang chain Vector stores and we initiate
the pine cone client with the key and
the environment that we have in the
environment file
then we take the variable texts which
consists of all the chunks of data we
want to store we take the embeddings
model and we take an index name and we
load those chunks on the embeddings to
Pine Cone and once we have the vector
stored in Pinecone we can ask questions
about the data stored what is magical
about an auto encoder and then we can do
a similarity search in Pinecone to get
the answer or to extract all the
relevant chunks
if we head over to Pine Cone we can see
that the index is here we can click on
it and inspect it
check the index info we have a total of
13 vectors in the vector store
all right so the last thing we're going
to do is we're going to have a brief
look at the concept of an agent
now if you head over to open AI chat GPT
plugins page you can see that they're
showcasing a python code interpreter
now we can actually do something similar
in langtune
so here I'm importing the create python
agent as well as the python Rebel tool
and the python webble from nankchain
then we instantiate a python agent
executor
using an open AI language model
and this allows us to having the
language model run python code
so here I want to find the roots of a
quadratic function and we see that the
agent executor is using numpy roots to
find the roots of this quadratic
function
alright so this video was meant to give
you a brief introduction to the Core
Concepts of langchain if you want to
follow along for a deep dive into the
concepts hit subscribe thanks for
watching
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