本笔记本展示了如何利用Langchain、Qdrant作为知识库以及OpenAI嵌入来实现问答系统。如果您不熟悉Qdrant，建议先查阅Getting_started_with_Qdrant_and_OpenAI.ipynb笔记本。
本笔记本展示了一个端到端流程，包括：
所有步骤都将简化为调用一些相应的Langchain方法。
为了本次练习，我们需要准备以下几项内容：
我们将使用在Docker容器中运行的本地Qdrant实例。最简单的启动方式是使用附带的[docker-compose.yaml]文件并运行以下命令：
! docker-compose up -dStarting qdrant_qdrant_1 ... [1Bting qdrant_qdrant_1 ... [32mdone[0m
我们可以通过运行一个简单的curl命令来验证服务器是否成功启动：
! curl http://localhost:6333{"title":"qdrant - vector search engine","version":"1.0.1"}本笔记本显然需要安装openai、langchain和qdrant-client软件包。
! pip install openai qdrant-client "langchain==0.0.100" wgetOpenAI API密钥用于文档和查询的向量化。
如果您没有OpenAI API密钥，可以从https://beta.openai.com/account/api-keys获取。
获取密钥后，请通过运行以下命令将其添加到环境变量中，命名为OPENAI_API_KEY：
! export OPENAI_API_KEY="your API key"# Test that your OpenAI API key is correctly set as an environment variable
# Note. if you run this notebook locally, you will need to reload your terminal and the notebook for the env variables to be live.
import os
# Note. alternatively you can set a temporary env variable like this:
# os.environ["OPENAI_API_KEY"] = "sk-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
if os.getenv("OPENAI_API_KEY") is not None:
print("OPENAI_API_KEY is ready")
else:
print("OPENAI_API_KEY environment variable not found")OPENAI_API_KEY is ready
在本节中，我们将加载包含一些自然问题及其答案的数据。所有数据将用于创建一个以Qdrant作为知识库的Langchain应用程序。
import wget
# All the examples come from https://ai.google.com/research/NaturalQuestions
# This is a sample of the training set that we download and extract for some
# further processing.
wget.download("https://storage.googleapis.com/dataset-natural-questions/questions.json")
wget.download("https://storage.googleapis.com/dataset-natural-questions/answers.json")100% [..............................................................................] 95372 / 95372
'answers.json'
import json
with open("questions.json", "r") as fp:
questions = json.load(fp)
with open("answers.json", "r") as fp:
answers = json.load(fp)print(questions[0])when is the last episode of season 8 of the walking dead
print(answers[0])No . overall No. in season Title Directed by Written by Original air date U.S. viewers ( millions ) 100 `` Mercy '' Greg Nicotero Scott M. Gimple October 22 , 2017 ( 2017 - 10 - 22 ) 11.44 Rick , Maggie , and Ezekiel rally their communities together to take down Negan . Gregory attempts to have the Hilltop residents side with Negan , but they all firmly stand behind Maggie . The group attacks the Sanctuary , taking down its fences and flooding the compound with walkers . With the Sanctuary defaced , everyone leaves except Gabriel , who reluctantly stays to save Gregory , but is left behind when Gregory abandons him . Surrounded by walkers , Gabriel hides in a trailer , where he is trapped inside with Negan . 101 `` The Damned '' Rosemary Rodriguez Matthew Negrete & Channing Powell October 29 , 2017 ( 2017 - 10 - 29 ) 8.92 Rick 's forces split into separate parties to attack several of the Saviors ' outposts , during which many members of the group are killed ; Eric is critically injured and rushed away by Aaron . Jesus stops Tara and Morgan from executing a group of surrendered Saviors . While clearing an outpost with Daryl , Rick is confronted and held at gunpoint by Morales , a survivor he met in the initial Atlanta camp , who is now with the Saviors . 102 `` Monsters '' Greg Nicotero Matthew Negrete & Channing Powell November 5 , 2017 ( 2017 - 11 - 05 ) 8.52 Daryl finds Morales threatening Rick and kills him ; the duo then pursue a group of Saviors who are transporting weapons to another outpost . Gregory returns to Hilltop , and after a heated argument , Maggie ultimately allows him back in the community . Eric dies from his injuries , leaving Aaron distraught . Despite Tara and Morgan 's objections , Jesus leads the group of surrendered Saviors to Hilltop . Ezekiel 's group attacks another Savior compound , during which several Kingdommers are shot while protecting Ezekiel . 103 `` Some Guy '' Dan Liu David Leslie Johnson November 12 , 2017 ( 2017 - 11 - 12 ) 8.69 Ezekiel 's group is overwhelmed by the Saviors , who kill all of them except for Ezekiel himself and Jerry . Carol clears the inside of the compound , killing all but two Saviors , who almost escape but are eventually caught by Rick and Daryl . En route to the Kingdom , Ezekiel , Jerry , and Carol are surrounded by walkers , but Shiva sacrifices herself to save them . The trio returns to the Kingdom , where Ezekiel 's confidence in himself as a leader has diminished . 104 5 `` The Big Scary U '' Michael E. Satrazemis Story by : Scott M. Gimple & David Leslie Johnson & Angela Kang Teleplay by : David Leslie Johnson & Angela Kang November 19 , 2017 ( 2017 - 11 - 19 ) 7.85 After confessing their sins to each other , Gabriel and Negan manage to escape from the trailer . Simon and the other lieutenants grow suspicious of each other , knowing that Rick 's forces must have inside information . The workers in the Sanctuary become increasingly frustrated with their living conditions , and a riot nearly ensues , until Negan returns and restores order . Gabriel is locked in a cell , where Eugene discovers him sick and suffering . Meanwhile , Rick and Daryl argue over how to take out the Saviors , leading Daryl to abandon Rick . 105 6 `` The King , the Widow , and Rick '' John Polson Angela Kang & Corey Reed November 26 , 2017 ( 2017 - 11 - 26 ) 8.28 Rick visits Jadis in hopes of convincing her to turn against Negan ; Jadis refuses , and locks Rick in a shipping container . Carl encounters Siddiq in the woods and recruits him to Alexandria . Daryl and Tara plot to deviate from Rick 's plans by destroying the Sanctuary . Ezekiel isolates himself at the Kingdom , where Carol tries to encourage him to be the leader his people need . Maggie has the group of captured Saviors placed in a holding area and forces Gregory to join them as punishment for betraying Hilltop . 106 7 `` Time for After '' Larry Teng Matthew Negrete & Corey Reed December 3 , 2017 ( 2017 - 12 - 03 ) 7.47 After learning of Dwight 's association with Rick 's group , Eugene affirms his loyalty to Negan and outlines a plan to get rid of the walkers surrounding the Sanctuary . With help from Morgan and Tara , Daryl drives a truck through the Sanctuary 's walls , flooding its interior with walkers , killing many Saviors . Rick finally convinces Jadis and the Scavengers to align with him , and they plan to force the Saviors to surrender . However , when they arrive at the Sanctuary , Rick is horrified to see the breached walls and no sign of the walker herd . 107 8 `` How It 's Gotta Be '' Michael E. Satrazemis David Leslie Johnson & Angela Kang December 10 , 2017 ( 2017 - 12 - 10 ) 7.89 Eugene 's plan allows the Saviors to escape , and separately , the Saviors waylay the Alexandria , Hilltop , and Kingdom forces . The Scavengers abandon Rick , after which he returns to Alexandria . Ezekiel ensures that the Kingdom residents are able to escape before locking himself in the community with the Saviors . Eugene aids Gabriel and Doctor Carson in escaping the Sanctuary in order to ease his conscience . Negan attacks Alexandria , but Carl devises a plan to allow the Alexandria residents to escape into the sewers . Carl reveals he was bitten by a walker while escorting Siddiq to Alexandria . 108 9 `` Honor '' Greg Nicotero Matthew Negrete & Channing Powell February 25 , 2018 ( 2018 - 02 - 25 ) 8.28 After the Saviors leave Alexandria , the survivors make for the Hilltop while Rick and Michonne stay behind to say their final goodbyes to a dying Carl , who pleads with Rick to build a better future alongside the Saviors before killing himself . In the Kingdom , Morgan and Carol launch a rescue mission for Ezekiel . Although they are successful and retake the Kingdom , the Saviors ' lieutenant Gavin is killed by Benjamin 's vengeful brother Henry . 109 10 `` The Lost and the Plunderers '' TBA TBA March 4 , 2018 ( 2018 - 03 - 04 ) TBD 110 11 `` Dead or Alive Or '' TBA TBA March 11 , 2018 ( 2018 - 03 - 11 ) TBD 111 12 `` The Key '' TBA TBA March 18 , 2018 ( 2018 - 03 - 18 ) TBD
Langchain已经与Qdrant集成，可为给定的文档列表执行所有索引操作。在我们的案例中，我们将存储已有的答案集合。
from langchain.vectorstores import Qdrant
from langchain.embeddings import OpenAIEmbeddings
from langchain import VectorDBQA, OpenAI
embeddings = OpenAIEmbeddings()
doc_store = Qdrant.from_texts(
answers, embeddings, host="localhost"
)在此阶段，所有可能的答案都已存储在Qdrant中，因此我们可以定义完整的问答链。
llm = OpenAI()
qa = VectorDBQA.from_chain_type(
llm=llm,
chain_type="stuff",
vectorstore=doc_store,
return_source_documents=False,
)将数据存入Qdrant后，我们就可以开始提问了。问题会被OpenAI模型自动向量化，生成的向量将用于在Qdrant中查找可能匹配的答案。检索到结果后，最相似的答案会被整合到发送给OpenAI大语言模型的提示词中。所有服务之间的通信关系如下图所示：
import random
random.seed(52)
selected_questions = random.choices(questions, k=5)for question in selected_questions:
print(">", question)
print(qa.run(question), end="\n\n")> where do frankenstein and the monster first meet Victor and the Creature first meet in the mountains. > who are the actors in fast and furious The actors in the Fast and Furious films are Vin Diesel, Paul Walker, Michelle Rodriguez, Jordana Brewster, Tyrese Gibson, Ludacris, Lucas Black, Sung Kang, Gal Gadot, Dwayne Johnson, Matt Schulze, Chad Lindberg, Johnny Strong, Eva Mendes, Devon Aoki, Nathalie Kelley, Bow Wow, Tego Calderón, Don Omar, Elsa Pataky, Kurt Russell, Nathalie Emmanuel, Scott Eastwood, Noel Gugliemi, Ja Rule, Thom Barry, Ted Levine, Minka Kelly, James Remar, Amaury Nolasco, Michael Ealy, MC Jin, Brian Goodman, Lynda Boyd, Jason Tobin, Neela, Liza Lapira, Alimi Ballard, Yorgo Constantine, Geoff Meed, Jeimy Osorio, Max William Crane, Charlie & Miller Kimsey, Eden Estrella, Romeo Santos, John Brotherton, Helen Mirren, Celestino Cornielle, Janmarco Santiago, Carlos De La Hoz, James Ayoub, Rick Yune, Cole Hauser, Brian Tee, John Ortiz, Luke Evans, Jason Statham, Charlize Theron, Reggie Lee, Mo Gallini, Roberto Sanchez, Leonardo > properties of red black tree in data structure Red black trees are a type of binary tree with a special set of properties. Each node is either red or black, the root is black, and if a node is red, then both its children are black. Every path from a given node to any of its descendant NIL nodes contains the same number of black nodes. The number of black nodes from the root to a node is the node's black depth, and the uniform number of black nodes in all paths from root to the leaves is called the black-height of the red-black tree. > who designed the national coat of arms of south africa Iaan Bekker > caravaggio's death of the virgin pamela askew I don't know.
Langchain中的stuff链类型使用了一个特定的提示模板，其中包含了问题和上下文文档。以下是默认提示模板的样子：
Use the following pieces of context to answer the question at the end. If you don't know the answer, just say that you don't know, don't try to make up an answer.
{context}
Question: {question}
Helpful Answer:不过，我们可以提供提示模板并改变OpenAI LLM的行为，同时仍使用stuff链类型。保持{context}和{question}作为占位符非常重要。
我们可以尝试使用不同的提示模板，这样模型：
from langchain.prompts import PromptTemplatecustom_prompt = """
Use the following pieces of context to answer the question at the end. Please provide
a short single-sentence summary answer only. If you don't know the answer or if it's
not present in given context, don't try to make up an answer, but suggest me a random
unrelated song title I could listen to.
Context: {context}
Question: {question}
Helpful Answer:
"""custom_prompt_template = PromptTemplate(
template=custom_prompt, input_variables=["context", "question"]
)custom_qa = VectorDBQA.from_chain_type(
llm=llm,
chain_type="stuff",
vectorstore=doc_store,
return_source_documents=False,
chain_type_kwargs={"prompt": custom_prompt_template},
)random.seed(41)
for question in random.choices(questions, k=5):
print(">", question)
print(custom_qa.run(question), end="\n\n")> what was uncle jesse's original last name on full house Uncle Jesse's original last name on Full House was Cochran. > when did the volcano erupt in indonesia 2018 No volcanic eruption is mentioned in the given context. Suggested Song: "Ring of Fire" by Johnny Cash. > what does a dualist way of thinking mean Dualist way of thinking means that the mind and body are separate entities, with the mind being a non-physical substance. > the first civil service commission in india was set up on the basis of recommendation of The first Civil Service Commission in India was not set up on the basis of a recommendation. > how old do you have to be to get a tattoo in utah In Utah, you must be at least 18 years old to get a tattoo.