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266d0daa8f0d-0 | .ipynb
.pdf
RetryOutputParser
RetryOutputParser#
While in some cases it is possible to fix any parsing mistakes by only looking at the output, in other cases it can’t. An example of this is when the output is not just in the incorrect format, but is partially complete. Consider the below example.
from langchain.prompts import PromptTemplate, ChatPromptTemplate, HumanMessagePromptTemplate
from langchain.llms import OpenAI
from langchain.chat_models import ChatOpenAI
from langchain.output_parsers import PydanticOutputParser, OutputFixingParser, RetryOutputParser
from pydantic import BaseModel, Field, validator
from typing import List
template = """Based on the user question, provide an Action and Action Input for what step should be taken.
{format_instructions}
Question: {query}
Response:"""
class Action(BaseModel):
action: str = Field(description="action to take")
action_input: str = Field(description="input to the action")
parser = PydanticOutputParser(pydantic_object=Action)
prompt = PromptTemplate(
template="Answer the user query.\n{format_instructions}\n{query}\n",
input_variables=["query"],
partial_variables={"format_instructions": parser.get_format_instructions()}
)
prompt_value = prompt.format_prompt(query="who is leo di caprios gf?")
bad_response = '{"action": "search"}' | /content/https://python.langchain.com/en/latest/modules/prompts/output_parsers/examples/retry.html |
266d0daa8f0d-1 | bad_response = '{"action": "search"}'
If we try to parse this response as is, we will get an error
parser.parse(bad_response)
---------------------------------------------------------------------------
ValidationError Traceback (most recent call last)
File ~/workplace/langchain/langchain/output_parsers/pydantic.py:24, in PydanticOutputParser.parse(self, text)
23 json_object = json.loads(json_str)
---> 24 return self.pydantic_object.parse_obj(json_object)
26 except (json.JSONDecodeError, ValidationError) as e:
File ~/.pyenv/versions/3.9.1/envs/langchain/lib/python3.9/site-packages/pydantic/main.py:527, in pydantic.main.BaseModel.parse_obj()
File ~/.pyenv/versions/3.9.1/envs/langchain/lib/python3.9/site-packages/pydantic/main.py:342, in pydantic.main.BaseModel.__init__()
ValidationError: 1 validation error for Action
action_input
field required (type=value_error.missing)
During handling of the above exception, another exception occurred:
OutputParserException Traceback (most recent call last)
Cell In[6], line 1
----> 1 parser.parse(bad_response) | /content/https://python.langchain.com/en/latest/modules/prompts/output_parsers/examples/retry.html |
266d0daa8f0d-2 | Cell In[6], line 1
----> 1 parser.parse(bad_response)
File ~/workplace/langchain/langchain/output_parsers/pydantic.py:29, in PydanticOutputParser.parse(self, text)
27 name = self.pydantic_object.__name__
28 msg = f"Failed to parse {name} from completion {text}. Got: {e}"
---> 29 raise OutputParserException(msg)
OutputParserException: Failed to parse Action from completion {"action": "search"}. Got: 1 validation error for Action
action_input
field required (type=value_error.missing)
If we try to use the OutputFixingParser to fix this error, it will be confused - namely, it doesn’t know what to actually put for action input.
fix_parser = OutputFixingParser.from_llm(parser=parser, llm=ChatOpenAI())
fix_parser.parse(bad_response)
Action(action='search', action_input='')
Instead, we can use the RetryOutputParser, which passes in the prompt (as well as the original output) to try again to get a better response.
from langchain.output_parsers import RetryWithErrorOutputParser
retry_parser = RetryWithErrorOutputParser.from_llm(parser=parser, llm=OpenAI(temperature=0))
retry_parser.parse_with_prompt(bad_response, prompt_value) | /content/https://python.langchain.com/en/latest/modules/prompts/output_parsers/examples/retry.html |
266d0daa8f0d-3 | Action(action='search', action_input='who is leo di caprios gf?')
previous
PydanticOutputParser
next
Structured Output Parser
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Apr 26, 2023. | /content/https://python.langchain.com/en/latest/modules/prompts/output_parsers/examples/retry.html |
738ac689bec8-0 | .ipynb
.pdf
PydanticOutputParser
PydanticOutputParser#
This output parser allows users to specify an arbitrary JSON schema and query LLMs for JSON outputs that conform to that schema.
Keep in mind that large language models are leaky abstractions! You’ll have to use an LLM with sufficient capacity to generate well-formed JSON. In the OpenAI family, DaVinci can do reliably but Curie’s ability already drops off dramatically.
Use Pydantic to declare your data model. Pydantic’s BaseModel like a Python dataclass, but with actual type checking + coercion.
from langchain.prompts import PromptTemplate, ChatPromptTemplate, HumanMessagePromptTemplate
from langchain.llms import OpenAI
from langchain.chat_models import ChatOpenAI
from langchain.output_parsers import PydanticOutputParser
from pydantic import BaseModel, Field, validator
from typing import List
model_name = 'text-davinci-003'
temperature = 0.0
model = OpenAI(model_name=model_name, temperature=temperature)
# Define your desired data structure.
class Joke(BaseModel):
setup: str = Field(description="question to set up a joke")
punchline: str = Field(description="answer to resolve the joke")
# You can add custom validation logic easily with Pydantic.
@validator('setup')
def question_ends_with_question_mark(cls, field):
if field[-1] != '?':
raise ValueError("Badly formed question!")
return field | /content/https://python.langchain.com/en/latest/modules/prompts/output_parsers/examples/pydantic.html |
738ac689bec8-1 | raise ValueError("Badly formed question!")
return field
# And a query intented to prompt a language model to populate the data structure.
joke_query = "Tell me a joke."
# Set up a parser + inject instructions into the prompt template.
parser = PydanticOutputParser(pydantic_object=Joke)
prompt = PromptTemplate(
template="Answer the user query.\n{format_instructions}\n{query}\n",
input_variables=["query"],
partial_variables={"format_instructions": parser.get_format_instructions()}
)
_input = prompt.format_prompt(query=joke_query)
output = model(_input.to_string())
parser.parse(output)
Joke(setup='Why did the chicken cross the road?', punchline='To get to the other side!')
# Here's another example, but with a compound typed field.
class Actor(BaseModel):
name: str = Field(description="name of an actor")
film_names: List[str] = Field(description="list of names of films they starred in")
actor_query = "Generate the filmography for a random actor."
parser = PydanticOutputParser(pydantic_object=Actor)
prompt = PromptTemplate(
template="Answer the user query.\n{format_instructions}\n{query}\n",
input_variables=["query"],
partial_variables={"format_instructions": parser.get_format_instructions()}
) | /content/https://python.langchain.com/en/latest/modules/prompts/output_parsers/examples/pydantic.html |
738ac689bec8-2 | )
_input = prompt.format_prompt(query=actor_query)
output = model(_input.to_string())
parser.parse(output)
Actor(name='Tom Hanks', film_names=['Forrest Gump', 'Saving Private Ryan', 'The Green Mile', 'Cast Away', 'Toy Story'])
previous
OutputFixingParser
next
RetryOutputParser
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Apr 26, 2023. | /content/https://python.langchain.com/en/latest/modules/prompts/output_parsers/examples/pydantic.html |
1acb0a74c007-0 | .ipynb
.pdf
OutputFixingParser
OutputFixingParser#
This output parser wraps another output parser and tries to fix any mmistakes
The Pydantic guardrail simply tries to parse the LLM response. If it does not parse correctly, then it errors.
But we can do other things besides throw errors. Specifically, we can pass the misformatted output, along with the formatted instructions, to the model and ask it to fix it.
For this example, we’ll use the above OutputParser. Here’s what happens if we pass it a result that does not comply with the schema:
from langchain.prompts import PromptTemplate, ChatPromptTemplate, HumanMessagePromptTemplate
from langchain.llms import OpenAI
from langchain.chat_models import ChatOpenAI
from langchain.output_parsers import PydanticOutputParser
from pydantic import BaseModel, Field, validator
from typing import List
class Actor(BaseModel):
name: str = Field(description="name of an actor")
film_names: List[str] = Field(description="list of names of films they starred in")
actor_query = "Generate the filmography for a random actor."
parser = PydanticOutputParser(pydantic_object=Actor)
misformatted = "{'name': 'Tom Hanks', 'film_names': ['Forrest Gump']}"
parser.parse(misformatted)
---------------------------------------------------------------------------
JSONDecodeError Traceback (most recent call last) | /content/https://python.langchain.com/en/latest/modules/prompts/output_parsers/examples/output_fixing_parser.html |
1acb0a74c007-1 | JSONDecodeError Traceback (most recent call last)
File ~/workplace/langchain/langchain/output_parsers/pydantic.py:23, in PydanticOutputParser.parse(self, text)
22 json_str = match.group()
---> 23 json_object = json.loads(json_str)
24 return self.pydantic_object.parse_obj(json_object)
File ~/.pyenv/versions/3.9.1/lib/python3.9/json/__init__.py:346, in loads(s, cls, object_hook, parse_float, parse_int, parse_constant, object_pairs_hook, **kw)
343 if (cls is None and object_hook is None and
344 parse_int is None and parse_float is None and
345 parse_constant is None and object_pairs_hook is None and not kw):
--> 346 return _default_decoder.decode(s)
347 if cls is None:
File ~/.pyenv/versions/3.9.1/lib/python3.9/json/decoder.py:337, in JSONDecoder.decode(self, s, _w)
333 """Return the Python representation of ``s`` (a ``str`` instance
334 containing a JSON document).
335
336 """
--> 337 obj, end = self.raw_decode(s, idx=_w(s, 0).end())
338 end = _w(s, end).end() | /content/https://python.langchain.com/en/latest/modules/prompts/output_parsers/examples/output_fixing_parser.html |
1acb0a74c007-2 | 338 end = _w(s, end).end()
File ~/.pyenv/versions/3.9.1/lib/python3.9/json/decoder.py:353, in JSONDecoder.raw_decode(self, s, idx)
352 try:
--> 353 obj, end = self.scan_once(s, idx)
354 except StopIteration as err:
JSONDecodeError: Expecting property name enclosed in double quotes: line 1 column 2 (char 1)
During handling of the above exception, another exception occurred:
OutputParserException Traceback (most recent call last)
Cell In[6], line 1
----> 1 parser.parse(misformatted)
File ~/workplace/langchain/langchain/output_parsers/pydantic.py:29, in PydanticOutputParser.parse(self, text)
27 name = self.pydantic_object.__name__
28 msg = f"Failed to parse {name} from completion {text}. Got: {e}"
---> 29 raise OutputParserException(msg)
OutputParserException: Failed to parse Actor from completion {'name': 'Tom Hanks', 'film_names': ['Forrest Gump']}. Got: Expecting property name enclosed in double quotes: line 1 column 2 (char 1)
Now we can construct and use a OutputFixingParser. This output parser takes as an argument another output parser but also an LLM with which to try to correct any formatting mistakes. | /content/https://python.langchain.com/en/latest/modules/prompts/output_parsers/examples/output_fixing_parser.html |
1acb0a74c007-3 | from langchain.output_parsers import OutputFixingParser
new_parser = OutputFixingParser.from_llm(parser=parser, llm=ChatOpenAI())
new_parser.parse(misformatted)
Actor(name='Tom Hanks', film_names=['Forrest Gump'])
previous
CommaSeparatedListOutputParser
next
PydanticOutputParser
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Apr 26, 2023. | /content/https://python.langchain.com/en/latest/modules/prompts/output_parsers/examples/output_fixing_parser.html |
729b68a30218-0 | .ipynb
.pdf
Structured Output Parser
Structured Output Parser#
While the Pydantic/JSON parser is more powerful, we initially experimented data structures having text fields only.
from langchain.output_parsers import StructuredOutputParser, ResponseSchema
from langchain.prompts import PromptTemplate, ChatPromptTemplate, HumanMessagePromptTemplate
from langchain.llms import OpenAI
from langchain.chat_models import ChatOpenAI
Here we define the response schema we want to receive.
response_schemas = [
ResponseSchema(name="answer", description="answer to the user's question"),
ResponseSchema(name="source", description="source used to answer the user's question, should be a website.")
]
output_parser = StructuredOutputParser.from_response_schemas(response_schemas)
We now get a string that contains instructions for how the response should be formatted, and we then insert that into our prompt.
format_instructions = output_parser.get_format_instructions()
prompt = PromptTemplate(
template="answer the users question as best as possible.\n{format_instructions}\n{question}",
input_variables=["question"],
partial_variables={"format_instructions": format_instructions}
)
We can now use this to format a prompt to send to the language model, and then parse the returned result.
model = OpenAI(temperature=0)
_input = prompt.format_prompt(question="what's the capital of france")
output = model(_input.to_string()) | /content/https://python.langchain.com/en/latest/modules/prompts/output_parsers/examples/structured.html |
729b68a30218-1 | output = model(_input.to_string())
output_parser.parse(output)
{'answer': 'Paris', 'source': 'https://en.wikipedia.org/wiki/Paris'}
And here’s an example of using this in a chat model
chat_model = ChatOpenAI(temperature=0)
prompt = ChatPromptTemplate(
messages=[
HumanMessagePromptTemplate.from_template("answer the users question as best as possible.\n{format_instructions}\n{question}")
],
input_variables=["question"],
partial_variables={"format_instructions": format_instructions}
)
_input = prompt.format_prompt(question="what's the capital of france")
output = chat_model(_input.to_messages())
output_parser.parse(output.content)
{'answer': 'Paris', 'source': 'https://en.wikipedia.org/wiki/Paris'}
previous
RetryOutputParser
next
Indexes
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Apr 26, 2023. | /content/https://python.langchain.com/en/latest/modules/prompts/output_parsers/examples/structured.html |
535b02a2dca1-0 | .ipynb
.pdf
CommaSeparatedListOutputParser
CommaSeparatedListOutputParser#
Here’s another parser strictly less powerful than Pydantic/JSON parsing.
from langchain.output_parsers import CommaSeparatedListOutputParser
from langchain.prompts import PromptTemplate, ChatPromptTemplate, HumanMessagePromptTemplate
from langchain.llms import OpenAI
from langchain.chat_models import ChatOpenAI
output_parser = CommaSeparatedListOutputParser()
format_instructions = output_parser.get_format_instructions()
prompt = PromptTemplate(
template="List five {subject}.\n{format_instructions}",
input_variables=["subject"],
partial_variables={"format_instructions": format_instructions}
)
model = OpenAI(temperature=0)
_input = prompt.format(subject="ice cream flavors")
output = model(_input)
output_parser.parse(output)
['Vanilla',
'Chocolate',
'Strawberry',
'Mint Chocolate Chip',
'Cookies and Cream']
previous
Output Parsers
next
OutputFixingParser
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Apr 26, 2023. | /content/https://python.langchain.com/en/latest/modules/prompts/output_parsers/examples/comma_separated.html |
bd4199454a86-0 | .rst
.pdf
Document Loaders
Document Loaders#
Note
Conceptual Guide
Combining language models with your own text data is a powerful way to differentiate them.
The first step in doing this is to load the data into “documents” - a fancy way of say some pieces of text.
This module is aimed at making this easy.
A primary driver of a lot of this is the Unstructured python package.
This package is a great way to transform all types of files - text, powerpoint, images, html, pdf, etc - into text data.
For detailed instructions on how to get set up with Unstructured, see installation guidelines here.
The following document loaders are provided:
CoNLL-U
Airbyte JSON
Apify Dataset
AZLyrics
Azure Blob Storage Container
Azure Blob Storage File
BigQuery Loader
Bilibili
Blackboard
Blockchain Document Loader
ChatGPT Data Loader
College Confidential
Confluence
Copy Paste
CSV Loader
DataFrame Loader
Diffbot
Directory Loader
Discord
DuckDB Loader
Email
EPubs
EverNote
Facebook Chat
Figma
GCS Directory
GCS File Storage
Git
GitBook
Google Drive
Gutenberg
Hacker News
HTML
HuggingFace dataset loader
iFixit
Images
Image captions
IMSDb
Markdown
Notebook
Notion
Notion DB Loader
Obsidian
PDF
PowerPoint
ReadTheDocs Documentation
Roam
s3 Directory
s3 File
Sitemap Loader
Slack (Local Exported Zipfile)
Subtitle Files
Telegram
Twitter
Unstructured File Loader
URL
Selenium URL Loader
Playwright URL Loader
Web Base
WhatsApp Chat
Word Documents
YouTube
previous
Getting Started
next
CoNLL-U
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Apr 26, 2023. | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders.html |
61ad92cb255f-0 | .ipynb
.pdf
Getting Started
Contents
One Line Index Creation
Walkthrough
Getting Started#
LangChain primary focuses on constructing indexes with the goal of using them as a Retriever. In order to best understand what this means, it’s worth highlighting what the base Retriever interface is. The BaseRetriever class in LangChain is as follows:
from abc import ABC, abstractmethod
from typing import List
from langchain.schema import Document
class BaseRetriever(ABC):
@abstractmethod
def get_relevant_documents(self, query: str) -> List[Document]:
"""Get texts relevant for a query.
Args:
query: string to find relevant texts for
Returns:
List of relevant documents
"""
It’s that simple! The get_relevant_documents method can be implemented however you see fit.
Of course, we also help construct what we think useful Retrievers are. The main type of Retriever that we focus on is a Vectorstore retriever. We will focus on that for the rest of this guide.
In order to understand what a vectorstore retriever is, it’s important to understand what a Vectorstore is. So let’s look at that.
By default, LangChain uses Chroma as the vectorstore to index and search embeddings. To walk through this tutorial, we’ll first need to install chromadb.
pip install chromadb
This example showcases question answering over documents.
We have chosen this as the example for getting started because it nicely combines a lot of different elements (Text splitters, embeddings, vectorstores) and then also shows how to use them in a chain.
Question answering over documents consists of four steps: | /content/https://python.langchain.com/en/latest/modules/indexes/getting_started.html |
61ad92cb255f-1 | Question answering over documents consists of four steps:
Create an index
Create a Retriever from that index
Create a question answering chain
Ask questions!
Each of the steps has multiple sub steps and potential configurations. In this notebook we will primarily focus on (1). We will start by showing the one-liner for doing so, but then break down what is actually going on.
First, let’s import some common classes we’ll use no matter what.
from langchain.chains import RetrievalQA
from langchain.llms import OpenAI
Next in the generic setup, let’s specify the document loader we want to use. You can download the state_of_the_union.txt file here
from langchain.document_loaders import TextLoader
loader = TextLoader('../state_of_the_union.txt', encoding='utf8')
One Line Index Creation#
To get started as quickly as possible, we can use the VectorstoreIndexCreator.
from langchain.indexes import VectorstoreIndexCreator
index = VectorstoreIndexCreator().from_loaders([loader])
Running Chroma using direct local API.
Using DuckDB in-memory for database. Data will be transient.
Now that the index is created, we can use it to ask questions of the data! Note that under the hood this is actually doing a few steps as well, which we will cover later in this guide.
query = "What did the president say about Ketanji Brown Jackson"
index.query(query) | /content/https://python.langchain.com/en/latest/modules/indexes/getting_started.html |
61ad92cb255f-2 | index.query(query)
" The president said that Ketanji Brown Jackson is one of the nation's top legal minds, a former top litigator in private practice, a former federal public defender, and from a family of public school educators and police officers. He also said that she is a consensus builder and has received a broad range of support from the Fraternal Order of Police to former judges appointed by Democrats and Republicans."
query = "What did the president say about Ketanji Brown Jackson"
index.query_with_sources(query)
{'question': 'What did the president say about Ketanji Brown Jackson',
'answer': " The president said that he nominated Circuit Court of Appeals Judge Ketanji Brown Jackson, one of the nation's top legal minds, to continue Justice Breyer's legacy of excellence, and that she has received a broad range of support from the Fraternal Order of Police to former judges appointed by Democrats and Republicans.\n",
'sources': '../state_of_the_union.txt'}
What is returned from the VectorstoreIndexCreator is VectorStoreIndexWrapper, which provides these nice query and query_with_sources functionality. If we just wanted to access the vectorstore directly, we can also do that.
index.vectorstore
<langchain.vectorstores.chroma.Chroma at 0x119aa5940>
If we then want to access the VectorstoreRetriever, we can do that with:
index.vectorstore.as_retriever() | /content/https://python.langchain.com/en/latest/modules/indexes/getting_started.html |
61ad92cb255f-3 | index.vectorstore.as_retriever()
VectorStoreRetriever(vectorstore=<langchain.vectorstores.chroma.Chroma object at 0x119aa5940>, search_kwargs={})
Walkthrough#
Okay, so what’s actually going on? How is this index getting created?
A lot of the magic is being hid in this VectorstoreIndexCreator. What is this doing?
There are three main steps going on after the documents are loaded:
Splitting documents into chunks
Creating embeddings for each document
Storing documents and embeddings in a vectorstore
Let’s walk through this in code
documents = loader.load()
Next, we will split the documents into chunks.
from langchain.text_splitter import CharacterTextSplitter
text_splitter = CharacterTextSplitter(chunk_size=1000, chunk_overlap=0)
texts = text_splitter.split_documents(documents)
We will then select which embeddings we want to use.
from langchain.embeddings import OpenAIEmbeddings
embeddings = OpenAIEmbeddings()
We now create the vectorstore to use as the index.
from langchain.vectorstores import Chroma
db = Chroma.from_documents(texts, embeddings)
Running Chroma using direct local API.
Using DuckDB in-memory for database. Data will be transient.
So that’s creating the index. Then, we expose this index in a retriever interface.
retriever = db.as_retriever()
Then, as before, we create a chain and use it to answer questions! | /content/https://python.langchain.com/en/latest/modules/indexes/getting_started.html |
61ad92cb255f-4 | Then, as before, we create a chain and use it to answer questions!
qa = RetrievalQA.from_chain_type(llm=OpenAI(), chain_type="stuff", retriever=retriever)
query = "What did the president say about Ketanji Brown Jackson"
qa.run(query)
" The President said that Judge Ketanji Brown Jackson is one of the nation's top legal minds, a former top litigator in private practice, a former federal public defender, and from a family of public school educators and police officers. He said she is a consensus builder and has received a broad range of support from organizations such as the Fraternal Order of Police and former judges appointed by Democrats and Republicans."
VectorstoreIndexCreator is just a wrapper around all this logic. It is configurable in the text splitter it uses, the embeddings it uses, and the vectorstore it uses. For example, you can configure it as below:
index_creator = VectorstoreIndexCreator(
vectorstore_cls=Chroma,
embedding=OpenAIEmbeddings(),
text_splitter=CharacterTextSplitter(chunk_size=1000, chunk_overlap=0)
)
Hopefully this highlights what is going on under the hood of VectorstoreIndexCreator. While we think it’s important to have a simple way to create indexes, we also think it’s important to understand what’s going on under the hood.
previous
Indexes
next
Document Loaders
Contents
One Line Index Creation
Walkthrough
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Apr 26, 2023. | /content/https://python.langchain.com/en/latest/modules/indexes/getting_started.html |
0e75cf4cf340-0 | .rst
.pdf
Vectorstores
Vectorstores#
Note
Conceptual Guide
Vectorstores are one of the most important components of building indexes.
For an introduction to vectorstores and generic functionality see:
Getting Started
We also have documentation for all the types of vectorstores that are supported.
Please see below for that list.
AnalyticDB
Annoy
AtlasDB
Chroma
Deep Lake
ElasticSearch
FAISS
Milvus
MyScale
OpenSearch
PGVector
Pinecone
Qdrant
Redis
SupabaseVectorStore
Weaviate
Zilliz
previous
TiktokenText Splitter
next
Getting Started
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Apr 26, 2023. | /content/https://python.langchain.com/en/latest/modules/indexes/vectorstores.html |
8a3d34c3d6d1-0 | .rst
.pdf
Text Splitters
Text Splitters#
Note
Conceptual Guide
When you want to deal with long pieces of text, it is necessary to split up that text into chunks.
As simple as this sounds, there is a lot of potential complexity here. Ideally, you want to keep the semantically related pieces of text together. What “semantically related” means could depend on the type of text.
This notebook showcases several ways to do that.
At a high level, text splitters work as following:
Split the text up into small, semantically meaningful chunks (often sentences).
Start combining these small chunks into a larger chunk until you reach a certain size (as measured by some function).
Once you reach that size, make that chunk its own piece of text and then start creating a new chunk of text with some overlap (to keep context between chunks).
That means there two different axes along which you can customize your text splitter:
How the text is split
How the chunk size is measured
For an introduction to the default text splitter and generic functionality see:
Getting Started
We also have documentation for all the types of text splitters that are supported.
Please see below for that list.
Character Text Splitter
Hugging Face Length Function
Latex Text Splitter
Markdown Text Splitter
NLTK Text Splitter
Python Code Text Splitter
RecursiveCharacterTextSplitter
Spacy Text Splitter
tiktoken (OpenAI) Length Function
TiktokenText Splitter
previous
YouTube
next
Getting Started
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Apr 26, 2023. | /content/https://python.langchain.com/en/latest/modules/indexes/text_splitters.html |
2fc5d215352b-0 | .rst
.pdf
Retrievers
Retrievers#
Note
Conceptual Guide
The retriever interface is a generic interface that makes it easy to combine documents with
language models. This interface exposes a get_relevant_documents method which takes in a query
(a string) and returns a list of documents.
Please see below for a list of all the retrievers supported.
ChatGPT Plugin Retriever
Contextual Compression Retriever
Stringing compressors and document transformers together
Databerry
ElasticSearch BM25
Metal
Pinecone Hybrid Search
SVM Retriever
TF-IDF Retriever
Time Weighted VectorStore Retriever
VectorStore Retriever
Weaviate Hybrid Search
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Zilliz
next
ChatGPT Plugin Retriever
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Apr 26, 2023. | /content/https://python.langchain.com/en/latest/modules/indexes/retrievers.html |
26d822eb982f-0 | .ipynb
.pdf
s3 Directory
Contents
Specifying a prefix
s3 Directory#
This covers how to load document objects from an s3 directory object.
from langchain.document_loaders import S3DirectoryLoader
#!pip install boto3
loader = S3DirectoryLoader("testing-hwc")
loader.load()
[Document(page_content='Lorem ipsum dolor sit amet.', lookup_str='', metadata={'source': '/var/folders/y6/8_bzdg295ld6s1_97_12m4lr0000gn/T/tmpaa9xl6ch/fake.docx'}, lookup_index=0)]
Specifying a prefix#
You can also specify a prefix for more finegrained control over what files to load.
loader = S3DirectoryLoader("testing-hwc", prefix="fake")
loader.load()
[Document(page_content='Lorem ipsum dolor sit amet.', lookup_str='', metadata={'source': '/var/folders/y6/8_bzdg295ld6s1_97_12m4lr0000gn/T/tmpujbkzf_l/fake.docx'}, lookup_index=0)]
previous
Roam
next
s3 File
Contents
Specifying a prefix
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Apr 26, 2023. | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/s3_directory.html |
90494dff95a1-0 | .ipynb
.pdf
Telegram
Telegram#
This notebook covers how to load data from Telegram into a format that can be ingested into LangChain.
from langchain.document_loaders import TelegramChatLoader
loader = TelegramChatLoader("example_data/telegram.json")
loader.load()
[Document(page_content="Henry on 2020-01-01T00:00:02: It's 2020...\n\nHenry on 2020-01-01T00:00:04: Fireworks!\n\nGrace 🧤 ðŸ\x8d’ on 2020-01-01T00:00:05: You're a minute late!\n\n", lookup_str='', metadata={'source': 'example_data/telegram.json'}, lookup_index=0)]
previous
Subtitle Files
next
Twitter
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Apr 26, 2023. | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/telegram.html |
4414d3cb1178-0 | .ipynb
.pdf
Copy Paste
Contents
Metadata
Copy Paste#
This notebook covers how to load a document object from something you just want to copy and paste. In this case, you don’t even need to use a DocumentLoader, but rather can just construct the Document directly.
from langchain.docstore.document import Document
text = "..... put the text you copy pasted here......"
doc = Document(page_content=text)
Metadata#
If you want to add metadata about the where you got this piece of text, you easily can with the metadata key.
metadata = {"source": "internet", "date": "Friday"}
doc = Document(page_content=text, metadata=metadata)
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Confluence
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CSV Loader
Contents
Metadata
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Apr 26, 2023. | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/copypaste.html |
a26c7bfe149a-0 | .ipynb
.pdf
YouTube
Contents
Add video info
YouTube loader from Google Cloud
Prerequisites
🧑 Instructions for ingesting your Google Docs data
YouTube#
How to load documents from YouTube transcripts.
from langchain.document_loaders import YoutubeLoader
# !pip install youtube-transcript-api
loader = YoutubeLoader.from_youtube_url("https://www.youtube.com/watch?v=QsYGlZkevEg", add_video_info=True)
loader.load()
Add video info#
# ! pip install pytube
loader = YoutubeLoader.from_youtube_url("https://www.youtube.com/watch?v=QsYGlZkevEg", add_video_info=True)
loader.load()
YouTube loader from Google Cloud#
Prerequisites#
Create a Google Cloud project or use an existing project
Enable the Youtube Api
Authorize credentials for desktop app
pip install --upgrade google-api-python-client google-auth-httplib2 google-auth-oauthlib youtube-transcript-api
🧑 Instructions for ingesting your Google Docs data#
By default, the GoogleDriveLoader expects the credentials.json file to be ~/.credentials/credentials.json, but this is configurable using the credentials_file keyword argument. Same thing with token.json. Note that token.json will be created automatically the first time you use the loader.
GoogleApiYoutubeLoader can load from a list of Google Docs document ids or a folder id. You can obtain your folder and document id from the URL: | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/youtube.html |
a26c7bfe149a-1 | Note depending on your set up, the service_account_path needs to be set up. See here for more details.
from langchain.document_loaders import GoogleApiClient, GoogleApiYoutubeLoader
# Init the GoogleApiClient
from pathlib import Path
google_api_client = GoogleApiClient(credentials_path=Path("your_path_creds.json"))
# Use a Channel
youtube_loader_channel = GoogleApiYoutubeLoader(google_api_client=google_api_client, channel_name="Reducible",captions_language="en")
# Use Youtube Ids
youtube_loader_ids = GoogleApiYoutubeLoader(google_api_client=google_api_client, video_ids=["TrdevFK_am4"], add_video_info=True)
# returns a list of Documents
youtube_loader_channel.load()
previous
Word Documents
next
Text Splitters
Contents
Add video info
YouTube loader from Google Cloud
Prerequisites
🧑 Instructions for ingesting your Google Docs data
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Apr 26, 2023. | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/youtube.html |
8c6bf65c23f0-0 | .ipynb
.pdf
Hacker News
Hacker News#
How to pull page data and comments from Hacker News
from langchain.document_loaders import HNLoader
loader = HNLoader("https://news.ycombinator.com/item?id=34817881")
data = loader.load()
data | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/hn.html |
8c6bf65c23f0-1 | data = loader.load()
data
[Document(page_content="delta_p_delta_x 18 hours ago \n | next [–] \n\nAstrophysical and cosmological simulations are often insightful. They're also very cross-disciplinary; besides the obvious astrophysics, there's networking and sysadmin, parallel computing and algorithm theory (so that the simulation programs are actually fast but still accurate), systems design, and even a bit of graphic design for the visualisations.Some of my favourite simulation projects:- IllustrisTNG: https://www.tng-project.org/- SWIFT: https://swift.dur.ac.uk/- CO5BOLD: https://www.astro.uu.se/~bf/co5bold_main.html (which produced these animations of a red-giant star: https://www.astro.uu.se/~bf/movie/AGBmovie.html)- AbacusSummit: https://abacussummit.readthedocs.io/en/latest/And I can add the simulations in the article, too.\n \nreply", lookup_str='', metadata={'source': 'https://news.ycombinator.com/item?id=34817881', 'title': 'What Lights the Universe’s Standard Candles?'}, lookup_index=0), | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/hn.html |
8c6bf65c23f0-2 | Document(page_content="andrewflnr 19 hours ago \n | prev | next [–] \n\nWhoa. I didn't know the accretion theory of Ia supernovae was dead, much less that it had been since 2011.\n \nreply", lookup_str='', metadata={'source': 'https://news.ycombinator.com/item?id=34817881', 'title': 'What Lights the Universe’s Standard Candles?'}, lookup_index=0),
Document(page_content='andreareina 18 hours ago \n | prev | next [–] \n\nThis seems to be the paper https://academic.oup.com/mnras/article/517/4/5260/6779709\n \nreply', lookup_str='', metadata={'source': 'https://news.ycombinator.com/item?id=34817881', 'title': 'What Lights the Universe’s Standard Candles?'}, lookup_index=0),
Document(page_content="andreareina 18 hours ago \n | prev [–] \n\nWouldn't double detonation show up as variance in the brightness?\n \nreply", lookup_str='', metadata={'source': 'https://news.ycombinator.com/item?id=34817881', 'title': 'What Lights the Universe’s Standard Candles?'}, lookup_index=0)]
previous
Gutenberg
next
HTML
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Apr 26, 2023. | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/hn.html |
7c891e54180d-0 | .ipynb
.pdf
CSV Loader
Contents
Customizing the csv parsing and loading
Specify a column to be used identify the document source
CSV Loader#
Load csv files with a single row per document.
from langchain.document_loaders.csv_loader import CSVLoader
loader = CSVLoader(file_path='./example_data/mlb_teams_2012.csv')
data = loader.load()
print(data) | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/csv.html |
7c891e54180d-1 | [Document(page_content='Team: Nationals\n"Payroll (millions)": 81.34\n"Wins": 98', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 0}, lookup_index=0), Document(page_content='Team: Reds\n"Payroll (millions)": 82.20\n"Wins": 97', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 1}, lookup_index=0), Document(page_content='Team: Yankees\n"Payroll (millions)": 197.96\n"Wins": 95', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 2}, lookup_index=0), Document(page_content='Team: Giants\n"Payroll (millions)": 117.62\n"Wins": 94', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 3}, lookup_index=0), Document(page_content='Team: Braves\n"Payroll (millions)": 83.31\n"Wins": 94', lookup_str='', metadata={'source': | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/csv.html |
7c891e54180d-2 | 94', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 4}, lookup_index=0), Document(page_content='Team: Athletics\n"Payroll (millions)": 55.37\n"Wins": 94', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 5}, lookup_index=0), Document(page_content='Team: Rangers\n"Payroll (millions)": 120.51\n"Wins": 93', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 6}, lookup_index=0), Document(page_content='Team: Orioles\n"Payroll (millions)": 81.43\n"Wins": 93', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 7}, lookup_index=0), Document(page_content='Team: Rays\n"Payroll (millions)": 64.17\n"Wins": 90', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 8}, lookup_index=0), Document(page_content='Team: | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/csv.html |
7c891e54180d-3 | 8}, lookup_index=0), Document(page_content='Team: Angels\n"Payroll (millions)": 154.49\n"Wins": 89', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 9}, lookup_index=0), Document(page_content='Team: Tigers\n"Payroll (millions)": 132.30\n"Wins": 88', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 10}, lookup_index=0), Document(page_content='Team: Cardinals\n"Payroll (millions)": 110.30\n"Wins": 88', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 11}, lookup_index=0), Document(page_content='Team: Dodgers\n"Payroll (millions)": 95.14\n"Wins": 86', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 12}, lookup_index=0), Document(page_content='Team: White Sox\n"Payroll (millions)": 96.92\n"Wins": 85', lookup_str='', metadata={'source': | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/csv.html |
7c891e54180d-4 | 85', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 13}, lookup_index=0), Document(page_content='Team: Brewers\n"Payroll (millions)": 97.65\n"Wins": 83', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 14}, lookup_index=0), Document(page_content='Team: Phillies\n"Payroll (millions)": 174.54\n"Wins": 81', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 15}, lookup_index=0), Document(page_content='Team: Diamondbacks\n"Payroll (millions)": 74.28\n"Wins": 81', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 16}, lookup_index=0), Document(page_content='Team: Pirates\n"Payroll (millions)": 63.43\n"Wins": 79', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 17}, lookup_index=0), Document(page_content='Team: | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/csv.html |
7c891e54180d-5 | 17}, lookup_index=0), Document(page_content='Team: Padres\n"Payroll (millions)": 55.24\n"Wins": 76', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 18}, lookup_index=0), Document(page_content='Team: Mariners\n"Payroll (millions)": 81.97\n"Wins": 75', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 19}, lookup_index=0), Document(page_content='Team: Mets\n"Payroll (millions)": 93.35\n"Wins": 74', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 20}, lookup_index=0), Document(page_content='Team: Blue Jays\n"Payroll (millions)": 75.48\n"Wins": 73', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 21}, lookup_index=0), Document(page_content='Team: Royals\n"Payroll (millions)": 60.91\n"Wins": 72', lookup_str='', metadata={'source': | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/csv.html |
7c891e54180d-6 | 72', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 22}, lookup_index=0), Document(page_content='Team: Marlins\n"Payroll (millions)": 118.07\n"Wins": 69', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 23}, lookup_index=0), Document(page_content='Team: Red Sox\n"Payroll (millions)": 173.18\n"Wins": 69', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 24}, lookup_index=0), Document(page_content='Team: Indians\n"Payroll (millions)": 78.43\n"Wins": 68', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 25}, lookup_index=0), Document(page_content='Team: Twins\n"Payroll (millions)": 94.08\n"Wins": 66', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 26}, lookup_index=0), Document(page_content='Team: | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/csv.html |
7c891e54180d-7 | 26}, lookup_index=0), Document(page_content='Team: Rockies\n"Payroll (millions)": 78.06\n"Wins": 64', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 27}, lookup_index=0), Document(page_content='Team: Cubs\n"Payroll (millions)": 88.19\n"Wins": 61', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 28}, lookup_index=0), Document(page_content='Team: Astros\n"Payroll (millions)": 60.65\n"Wins": 55', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 29}, lookup_index=0)] | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/csv.html |
7c891e54180d-8 | Customizing the csv parsing and loading#
See the csv module documentation for more information of what csv args are supported.
loader = CSVLoader(file_path='./example_data/mlb_teams_2012.csv', csv_args={
'delimiter': ',',
'quotechar': '"',
'fieldnames': ['MLB Team', 'Payroll in millions', 'Wins']
})
data = loader.load()
print(data) | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/csv.html |
7c891e54180d-9 | [Document(page_content='MLB Team: Team\nPayroll in millions: "Payroll (millions)"\nWins: "Wins"', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 0}, lookup_index=0), Document(page_content='MLB Team: Nationals\nPayroll in millions: 81.34\nWins: 98', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 1}, lookup_index=0), Document(page_content='MLB Team: Reds\nPayroll in millions: 82.20\nWins: 97', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 2}, lookup_index=0), Document(page_content='MLB Team: Yankees\nPayroll in millions: 197.96\nWins: 95', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 3}, lookup_index=0), Document(page_content='MLB Team: Giants\nPayroll in millions: 117.62\nWins: 94', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/csv.html |
7c891e54180d-10 | 'row': 4}, lookup_index=0), Document(page_content='MLB Team: Braves\nPayroll in millions: 83.31\nWins: 94', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 5}, lookup_index=0), Document(page_content='MLB Team: Athletics\nPayroll in millions: 55.37\nWins: 94', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 6}, lookup_index=0), Document(page_content='MLB Team: Rangers\nPayroll in millions: 120.51\nWins: 93', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 7}, lookup_index=0), Document(page_content='MLB Team: Orioles\nPayroll in millions: 81.43\nWins: 93', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 8}, lookup_index=0), Document(page_content='MLB Team: Rays\nPayroll in millions: 64.17\nWins: 90', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/csv.html |
7c891e54180d-11 | 'row': 9}, lookup_index=0), Document(page_content='MLB Team: Angels\nPayroll in millions: 154.49\nWins: 89', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 10}, lookup_index=0), Document(page_content='MLB Team: Tigers\nPayroll in millions: 132.30\nWins: 88', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 11}, lookup_index=0), Document(page_content='MLB Team: Cardinals\nPayroll in millions: 110.30\nWins: 88', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 12}, lookup_index=0), Document(page_content='MLB Team: Dodgers\nPayroll in millions: 95.14\nWins: 86', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 13}, lookup_index=0), Document(page_content='MLB Team: White Sox\nPayroll in millions: 96.92\nWins: 85', lookup_str='', metadata={'source': | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/csv.html |
7c891e54180d-12 | 85', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 14}, lookup_index=0), Document(page_content='MLB Team: Brewers\nPayroll in millions: 97.65\nWins: 83', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 15}, lookup_index=0), Document(page_content='MLB Team: Phillies\nPayroll in millions: 174.54\nWins: 81', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 16}, lookup_index=0), Document(page_content='MLB Team: Diamondbacks\nPayroll in millions: 74.28\nWins: 81', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 17}, lookup_index=0), Document(page_content='MLB Team: Pirates\nPayroll in millions: 63.43\nWins: 79', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 18}, lookup_index=0), Document(page_content='MLB Team: Padres\nPayroll in millions: | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/csv.html |
7c891e54180d-13 | Document(page_content='MLB Team: Padres\nPayroll in millions: 55.24\nWins: 76', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 19}, lookup_index=0), Document(page_content='MLB Team: Mariners\nPayroll in millions: 81.97\nWins: 75', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 20}, lookup_index=0), Document(page_content='MLB Team: Mets\nPayroll in millions: 93.35\nWins: 74', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 21}, lookup_index=0), Document(page_content='MLB Team: Blue Jays\nPayroll in millions: 75.48\nWins: 73', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 22}, lookup_index=0), Document(page_content='MLB Team: Royals\nPayroll in millions: 60.91\nWins: 72', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 23}, | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/csv.html |
7c891e54180d-14 | 'row': 23}, lookup_index=0), Document(page_content='MLB Team: Marlins\nPayroll in millions: 118.07\nWins: 69', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 24}, lookup_index=0), Document(page_content='MLB Team: Red Sox\nPayroll in millions: 173.18\nWins: 69', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 25}, lookup_index=0), Document(page_content='MLB Team: Indians\nPayroll in millions: 78.43\nWins: 68', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 26}, lookup_index=0), Document(page_content='MLB Team: Twins\nPayroll in millions: 94.08\nWins: 66', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 27}, lookup_index=0), Document(page_content='MLB Team: Rockies\nPayroll in millions: 78.06\nWins: 64', lookup_str='', metadata={'source': | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/csv.html |
7c891e54180d-15 | 64', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 28}, lookup_index=0), Document(page_content='MLB Team: Cubs\nPayroll in millions: 88.19\nWins: 61', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 29}, lookup_index=0), Document(page_content='MLB Team: Astros\nPayroll in millions: 60.65\nWins: 55', lookup_str='', metadata={'source': './example_data/mlb_teams_2012.csv', 'row': 30}, lookup_index=0)] | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/csv.html |
7c891e54180d-16 | Specify a column to be used identify the document source#
Use the source_column argument to specify a column to be set as the source for the document created from each row. Otherwise file_path will be used as the source for all documents created from the csv file.
This is useful when using documents loaded from CSV files for chains that answer questions using sources.
loader = CSVLoader(file_path='./example_data/mlb_teams_2012.csv', source_column="Team")
data = loader.load()
print(data) | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/csv.html |
7c891e54180d-17 | [Document(page_content='Team: Nationals\n"Payroll (millions)": 81.34\n"Wins": 98', lookup_str='', metadata={'source': 'Nationals', 'row': 0}, lookup_index=0), Document(page_content='Team: Reds\n"Payroll (millions)": 82.20\n"Wins": 97', lookup_str='', metadata={'source': 'Reds', 'row': 1}, lookup_index=0), Document(page_content='Team: Yankees\n"Payroll (millions)": 197.96\n"Wins": 95', lookup_str='', metadata={'source': 'Yankees', 'row': 2}, lookup_index=0), Document(page_content='Team: Giants\n"Payroll (millions)": 117.62\n"Wins": 94', lookup_str='', metadata={'source': 'Giants', 'row': 3}, lookup_index=0), Document(page_content='Team: Braves\n"Payroll (millions)": 83.31\n"Wins": 94', lookup_str='', metadata={'source': 'Braves', 'row': 4}, lookup_index=0), Document(page_content='Team: Athletics\n"Payroll (millions)": 55.37\n"Wins": 94', lookup_str='', metadata={'source': 'Athletics', | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/csv.html |
7c891e54180d-18 | metadata={'source': 'Athletics', 'row': 5}, lookup_index=0), Document(page_content='Team: Rangers\n"Payroll (millions)": 120.51\n"Wins": 93', lookup_str='', metadata={'source': 'Rangers', 'row': 6}, lookup_index=0), Document(page_content='Team: Orioles\n"Payroll (millions)": 81.43\n"Wins": 93', lookup_str='', metadata={'source': 'Orioles', 'row': 7}, lookup_index=0), Document(page_content='Team: Rays\n"Payroll (millions)": 64.17\n"Wins": 90', lookup_str='', metadata={'source': 'Rays', 'row': 8}, lookup_index=0), Document(page_content='Team: Angels\n"Payroll (millions)": 154.49\n"Wins": 89', lookup_str='', metadata={'source': 'Angels', 'row': 9}, lookup_index=0), Document(page_content='Team: Tigers\n"Payroll (millions)": 132.30\n"Wins": 88', lookup_str='', metadata={'source': 'Tigers', 'row': 10}, lookup_index=0), Document(page_content='Team: Cardinals\n"Payroll (millions)": 110.30\n"Wins": | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/csv.html |
7c891e54180d-19 | (millions)": 110.30\n"Wins": 88', lookup_str='', metadata={'source': 'Cardinals', 'row': 11}, lookup_index=0), Document(page_content='Team: Dodgers\n"Payroll (millions)": 95.14\n"Wins": 86', lookup_str='', metadata={'source': 'Dodgers', 'row': 12}, lookup_index=0), Document(page_content='Team: White Sox\n"Payroll (millions)": 96.92\n"Wins": 85', lookup_str='', metadata={'source': 'White Sox', 'row': 13}, lookup_index=0), Document(page_content='Team: Brewers\n"Payroll (millions)": 97.65\n"Wins": 83', lookup_str='', metadata={'source': 'Brewers', 'row': 14}, lookup_index=0), Document(page_content='Team: Phillies\n"Payroll (millions)": 174.54\n"Wins": 81', lookup_str='', metadata={'source': 'Phillies', 'row': 15}, lookup_index=0), Document(page_content='Team: Diamondbacks\n"Payroll (millions)": 74.28\n"Wins": 81', lookup_str='', metadata={'source': 'Diamondbacks', 'row': 16}, | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/csv.html |
7c891e54180d-20 | 'Diamondbacks', 'row': 16}, lookup_index=0), Document(page_content='Team: Pirates\n"Payroll (millions)": 63.43\n"Wins": 79', lookup_str='', metadata={'source': 'Pirates', 'row': 17}, lookup_index=0), Document(page_content='Team: Padres\n"Payroll (millions)": 55.24\n"Wins": 76', lookup_str='', metadata={'source': 'Padres', 'row': 18}, lookup_index=0), Document(page_content='Team: Mariners\n"Payroll (millions)": 81.97\n"Wins": 75', lookup_str='', metadata={'source': 'Mariners', 'row': 19}, lookup_index=0), Document(page_content='Team: Mets\n"Payroll (millions)": 93.35\n"Wins": 74', lookup_str='', metadata={'source': 'Mets', 'row': 20}, lookup_index=0), Document(page_content='Team: Blue Jays\n"Payroll (millions)": 75.48\n"Wins": 73', lookup_str='', metadata={'source': 'Blue Jays', 'row': 21}, lookup_index=0), Document(page_content='Team: Royals\n"Payroll (millions)": 60.91\n"Wins": 72', | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/csv.html |
7c891e54180d-21 | (millions)": 60.91\n"Wins": 72', lookup_str='', metadata={'source': 'Royals', 'row': 22}, lookup_index=0), Document(page_content='Team: Marlins\n"Payroll (millions)": 118.07\n"Wins": 69', lookup_str='', metadata={'source': 'Marlins', 'row': 23}, lookup_index=0), Document(page_content='Team: Red Sox\n"Payroll (millions)": 173.18\n"Wins": 69', lookup_str='', metadata={'source': 'Red Sox', 'row': 24}, lookup_index=0), Document(page_content='Team: Indians\n"Payroll (millions)": 78.43\n"Wins": 68', lookup_str='', metadata={'source': 'Indians', 'row': 25}, lookup_index=0), Document(page_content='Team: Twins\n"Payroll (millions)": 94.08\n"Wins": 66', lookup_str='', metadata={'source': 'Twins', 'row': 26}, lookup_index=0), Document(page_content='Team: Rockies\n"Payroll (millions)": 78.06\n"Wins": 64', lookup_str='', metadata={'source': 'Rockies', 'row': 27}, lookup_index=0), | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/csv.html |
7c891e54180d-22 | 'Rockies', 'row': 27}, lookup_index=0), Document(page_content='Team: Cubs\n"Payroll (millions)": 88.19\n"Wins": 61', lookup_str='', metadata={'source': 'Cubs', 'row': 28}, lookup_index=0), Document(page_content='Team: Astros\n"Payroll (millions)": 60.65\n"Wins": 55', lookup_str='', metadata={'source': 'Astros', 'row': 29}, lookup_index=0)] | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/csv.html |
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DataFrame Loader
Contents
Customizing the csv parsing and loading
Specify a column to be used identify the document source
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Apr 26, 2023. | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/csv.html |
7b0dfe8ade09-0 | .ipynb
.pdf
PDF
Contents
Using PyPDF
Using Unstructured
Retain Elements
Fetching remote PDFs using Unstructured
Using PDFMiner
Using PDFMiner to generate HTML text
Using PyMuPDF
PDF#
This covers how to load pdfs into a document format that we can use downstream.
Using PyPDF#
Load PDF using pypdf into array of documents, where each document contains the page content and metadata with page number.
from langchain.document_loaders import PyPDFLoader
loader = PyPDFLoader("example_data/layout-parser-paper.pdf")
pages = loader.load_and_split()
pages[0] | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-1 | Document(page_content='LayoutParser : A Uni\x0ced Toolkit for Deep\nLearning Based Document Image Analysis\nZejiang Shen1( \x00), Ruochen Zhang2, Melissa Dell3, Benjamin Charles Germain\nLee4, Jacob Carlson3, and Weining Li5\n1Allen Institute for AI\[email protected]\n2Brown University\nruochen [email protected]\n3Harvard University\nfmelissadell,jacob carlson [email protected]\n4University of Washington\[email protected]\n5University of Waterloo\[email protected]\nAbstract. Recent advances in document image analysis (DIA) have been\nprimarily driven by the application of neural networks. Ideally, research\noutcomes could be easily deployed in production and extended for further\ninvestigation. However, various factors like loosely organized codebases\nand sophisticated model con\x0cgurations complicate the easy reuse of im-\nportant innovations by a wide audience. Though there have been on-going\ne\x0borts to improve reusability and simplify deep learning (DL) model\ndevelopment in disciplines like natural language processing and computer\nvision, none of them are optimized for challenges in the domain of DIA.\nThis represents a major gap in the existing toolkit, as DIA is central to\nacademic research across a wide range of disciplines in the social sciences\nand humanities. This paper introduces LayoutParser , an | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-2 | the social sciences\nand humanities. This paper introduces LayoutParser , an open-source\nlibrary for streamlining the usage of DL in DIA research and applica-\ntions. The core LayoutParser library comes with a set of simple and\nintuitive interfaces for applying and customizing DL models for layout de-\ntection, character recognition, and many other document processing tasks.\nTo promote extensibility, LayoutParser also incorporates a community\nplatform for sharing both pre-trained models and full document digiti-\nzation pipelines. We demonstrate that LayoutParser is helpful for both\nlightweight and large-scale digitization pipelines in real-word use cases.\nThe library is publicly available at https://layout-parser.github.io .\nKeywords: Document Image Analysis ·Deep Learning ·Layout Analysis\n·Character Recognition ·Open Source library ·Toolkit.\n1 Introduction\nDeep Learning(DL)-based approaches are the state-of-the-art for a wide range of\ndocument image analysis (DIA) tasks including document image classi\x0ccation [ 11,arXiv:2103.15348v2 [cs.CV] 21 Jun 2021', lookup_str='', metadata={'source': 'example_data/layout-parser-paper.pdf', 'page': '0'}, lookup_index=0) | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-3 | An advantage of this approach is that documents can be retrieved with page numbers.
from langchain.vectorstores import FAISS
from langchain.embeddings.openai import OpenAIEmbeddings
faiss_index = FAISS.from_documents(pages, OpenAIEmbeddings())
docs = faiss_index.similarity_search("How will the community be engaged?", k=2)
for doc in docs:
print(str(doc.metadata["page"]) + ":", doc.page_content)
9: 10 Z. Shen et al.
Fig. 4: Illustration of (a) the original historical Japanese document with layout
detection results and (b) a recreated version of the document image that achieves
much better character recognition recall. The reorganization algorithm rearranges
the tokens based on the their detected bounding boxes given a maximum allowed
height.
4LayoutParser Community Platform
Another focus of LayoutParser is promoting the reusability of layout detection
models and full digitization pipelines. Similar to many existing deep learning
libraries, LayoutParser comes with a community model hub for distributing
layout models. End-users can upload their self-trained models to the model hub,
and these models can be loaded into a similar interface as the currently available
LayoutParser pre-trained models. For example, the model trained on the News
Navigator dataset [17] has been incorporated in the model hub.
Beyond DL models, LayoutParser also promotes the sharing of entire doc-
ument digitization pipelines. For example, sometimes the pipeline requires the
combination of multiple DL models to achieve better accuracy. Currently, pipelines
are mainly described in academic papers and implementations are often not pub- | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-4 | are mainly described in academic papers and implementations are often not pub-
licly available. To this end, the LayoutParser community platform also enables
the sharing of layout pipelines to promote the discussion and reuse of techniques.
For each shared pipeline, it has a dedicated project page, with links to the source
code, documentation, and an outline of the approaches. A discussion panel is
provided for exchanging ideas. Combined with the core LayoutParser library,
users can easily build reusable components based on the shared pipelines and
apply them to solve their unique problems.
5 Use Cases
The core objective of LayoutParser is to make it easier to create both large-scale
and light-weight document digitization pipelines. Large-scale document processing
3: 4 Z. Shen et al.
Efficient Data AnnotationC u s t o m i z e d M o d e l T r a i n i n gModel Cust omizationDI A Model HubDI A Pipeline SharingCommunity PlatformLa y out Detection ModelsDocument Images
T h e C o r e L a y o u t P a r s e r L i b r a r yOCR ModuleSt or age & VisualizationLa y out Data Structur e
Fig. 1: The overall architecture of LayoutParser . For an input document image,
the core LayoutParser library provides a set of o
-the-shelf tools for layout
detection, OCR, visualization, and storage, backed by a carefully designed layout
data structure. LayoutParser also supports high level customization via ecient
layout annotation and model training functions. These improve model accuracy
on the target samples. The community platform enables the easy sharing of DIA
models and whole digitization pipelines to promote reusability and reproducibility. | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-5 | models and whole digitization pipelines to promote reusability and reproducibility.
A collection of detailed documentation, tutorials and exemplar projects make
LayoutParser easy to learn and use.
AllenNLP [ 8] and transformers [ 34] have provided the community with complete
DL-based support for developing and deploying models for general computer
vision and natural language processing problems. LayoutParser , on the other
hand, specializes speci
cally in DIA tasks. LayoutParser is also equipped with a
community platform inspired by established model hubs such as Torch Hub [23]
andTensorFlow Hub [1]. It enables the sharing of pretrained models as well as
full document processing pipelines that are unique to DIA tasks.
There have been a variety of document data collections to facilitate the
development of DL models. Some examples include PRImA [ 3](magazine layouts),
PubLayNet [ 38](academic paper layouts), Table Bank [ 18](tables in academic
papers), Newspaper Navigator Dataset [ 16,17](newspaper
gure layouts) and
HJDataset [31](historical Japanese document layouts). A spectrum of models
trained on these datasets are currently available in the LayoutParser model zoo
to support di
erent use cases.
3 The Core LayoutParser Library
At the core of LayoutParser is an o
-the-shelf toolkit that streamlines DL-
based document image analysis. Five components support a simple interface
with comprehensive functionalities: 1) The layout detection models enable using
pre-trained or self-trained DL models for layout detection with just four lines
of code. 2) The detected layout information is stored in carefully engineered
Using Unstructured#
from langchain.document_loaders import UnstructuredPDFLoader | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-6 | from langchain.document_loaders import UnstructuredPDFLoader
loader = UnstructuredPDFLoader("example_data/layout-parser-paper.pdf")
data = loader.load()
Retain Elements#
Under the hood, Unstructured creates different “elements” for different chunks of text. By default we combine those together, but you can easily keep that separation by specifying mode="elements".
loader = UnstructuredPDFLoader("example_data/layout-parser-paper.pdf", mode="elements")
data = loader.load()
data[0] | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-7 | Document(page_content='LayoutParser: A Unified Toolkit for Deep\nLearning Based Document Image Analysis\nZejiang Shen1 (�), Ruochen Zhang2, Melissa Dell3, Benjamin Charles Germain\nLee4, Jacob Carlson3, and Weining Li5\n1 Allen Institute for AI\[email protected]\n2 Brown University\nruochen [email protected]\n3 Harvard University\n{melissadell,jacob carlson}@fas.harvard.edu\n4 University of Washington\[email protected]\n5 University of Waterloo\[email protected]\nAbstract. Recent advances in document image analysis (DIA) have been\nprimarily driven by the application of neural networks. Ideally, research\noutcomes could be easily deployed in production and extended for further\ninvestigation. However, various factors like loosely organized codebases\nand sophisticated model configurations complicate the easy reuse of im-\nportant innovations by a wide audience. Though there have been on-going\nefforts to improve reusability and simplify deep learning (DL) model\ndevelopment in disciplines like natural language processing and computer\nvision, none of them are optimized for challenges in the domain of DIA.\nThis represents a major gap in the existing toolkit, as DIA is central to\nacademic research across a wide range of disciplines in the social sciences\nand humanities. This paper introduces LayoutParser, an open-source\nlibrary for streamlining the usage of DL in DIA research | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-8 | open-source\nlibrary for streamlining the usage of DL in DIA research and applica-\ntions. The core LayoutParser library comes with a set of simple and\nintuitive interfaces for applying and customizing DL models for layout de-\ntection, character recognition, and many other document processing tasks.\nTo promote extensibility, LayoutParser also incorporates a community\nplatform for sharing both pre-trained models and full document digiti-\nzation pipelines. We demonstrate that LayoutParser is helpful for both\nlightweight and large-scale digitization pipelines in real-word use cases.\nThe library is publicly available at https://layout-parser.github.io.\nKeywords: Document Image Analysis · Deep Learning · Layout Analysis\n· Character Recognition · Open Source library · Toolkit.\n1\nIntroduction\nDeep Learning(DL)-based approaches are the state-of-the-art for a wide range of\ndocument image analysis (DIA) tasks including document image classification [11,\narXiv:2103.15348v2 [cs.CV] 21 Jun 2021\n', lookup_str='', metadata={'file_path': 'example_data/layout-parser-paper.pdf', 'page_number': 1, 'total_pages': 16, 'format': 'PDF 1.5', 'title': '', 'author': '', 'subject': '', 'keywords': '', 'creator': 'LaTeX with hyperref', 'producer': 'pdfTeX-1.40.21', | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-9 | hyperref', 'producer': 'pdfTeX-1.40.21', 'creationDate': 'D:20210622012710Z', 'modDate': 'D:20210622012710Z', 'trapped': '', 'encryption': None}, lookup_index=0) | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-10 | Fetching remote PDFs using Unstructured#
This covers how to load online pdfs into a document format that we can use downstream. This can be used for various online pdf sites such as https://open.umn.edu/opentextbooks/textbooks/ and https://arxiv.org/archive/
Note: all other pdf loaders can also be used to fetch remote PDFs, but OnlinePDFLoader is a legacy function, and works specifically with UnstructuredPDFLoader.
from langchain.document_loaders import OnlinePDFLoader
loader = OnlinePDFLoader("https://arxiv.org/pdf/2302.03803.pdf")
data = loader.load()
print(data) | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-11 | [Document(page_content='A WEAK ( k, k ) -LEFSCHETZ THEOREM FOR PROJECTIVE TORIC ORBIFOLDS\n\nWilliam D. Montoya\n\nInstituto de Matem´atica, Estat´ıstica e Computa¸c˜ao Cient´ıfica,\n\nIn [3] we proved that, under suitable conditions, on a very general codimension s quasi- smooth intersection subvariety X in a projective toric orbifold P d Σ with d + s = 2 ( k + 1 ) the Hodge conjecture holds, that is, every ( p, p ) -cohomology class, under the Poincar´e duality is a rational linear combination of fundamental classes of algebraic subvarieties of X . The proof of the above-mentioned result relies, for p ≠ d + 1 − s , on a Lefschetz\n\nKeywords: (1,1)- Lefschetz theorem, Hodge conjecture, toric varieties, complete intersection Email: [email protected]\n\ntheorem ([7]) and the Hard Lefschetz theorem for projective orbifolds ([11]). When p = d + 1 − s the proof relies on the Cayley trick, a trick which associates to X a quasi-smooth hypersurface Y in a projective vector bundle, and the Cayley Proposition (4.3) which gives an isomorphism of some primitive cohomologies (4.2) of X and Y . The Cayley trick, following the philosophy of Mavlyutov in [7], reduces results known for quasi-smooth hypersurfaces to quasi-smooth | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-12 | [7], reduces results known for quasi-smooth hypersurfaces to quasi-smooth intersection subvarieties. The idea in this paper goes the other way around, we translate some results for quasi-smooth intersection subvarieties to\n\nAcknowledgement. I thank Prof. Ugo Bruzzo and Tiago Fonseca for useful discus- sions. I also acknowledge support from FAPESP postdoctoral grant No. 2019/23499-7.\n\nLet M be a free abelian group of rank d , let N = Hom ( M, Z ) , and N R = N ⊗ Z R .\n\nif there exist k linearly independent primitive elements e\n\n, . . . , e k ∈ N such that σ = { µ\n\ne\n\n+ ⋯ + µ k e k } . • The generators e i are integral if for every i and any nonnegative rational number µ the product µe i is in N only if µ is an integer. • Given two rational simplicial cones σ , σ ′ one says that σ ′ is a face of σ ( σ ′ < σ ) if the set of integral generators of σ ′ is a subset of the set of integral generators of σ . • A finite set Σ = { σ\n\n, . . . , σ t } of rational simplicial cones is called a rational simplicial complete d -dimensional fan if:\n\nall faces of cones in Σ are in Σ ;\n\nif σ, σ ′ ∈ Σ then σ ∩ σ ′ < σ and σ ∩ σ ′ < σ ′ ;\n\nN R | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-13 | < σ and σ ∩ σ ′ < σ ′ ;\n\nN R = σ\n\n∪ ⋅ ⋅ ⋅ ∪ σ t .\n\nA rational simplicial complete d -dimensional fan Σ defines a d -dimensional toric variety P d Σ having only orbifold singularities which we assume to be projective. Moreover, T ∶ = N ⊗ Z C ∗ ≃ ( C ∗ ) d is the torus action on P d Σ . We denote by Σ ( i ) the i -dimensional cones\n\nFor a cone σ ∈ Σ, ˆ σ is the set of 1-dimensional cone in Σ that are not contained in σ\n\nand x ˆ σ ∶ = ∏ ρ ∈ ˆ σ x ρ is the associated monomial in S .\n\nDefinition 2.2. The irrelevant ideal of P d Σ is the monomial ideal B Σ ∶ =< x ˆ σ ∣ σ ∈ Σ > and the zero locus Z ( Σ ) ∶ = V ( B Σ ) in the affine space A d ∶ = Spec ( S ) is the irrelevant locus.\n\nProposition 2.3 (Theorem 5.1.11 [5]) . The toric variety P d Σ is a categorical quotient A d ∖ Z ( Σ ) by the group Hom ( Cl ( Σ ) , C ∗ ) and the group action is induced by the Cl ( Σ ) - grading of S .\n\nNow we give a brief introduction to complex orbifolds and we mention the needed theorems for the next section. Namely: de Rham theorem and Dolbeault theorem for complex | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-14 | next section. Namely: de Rham theorem and Dolbeault theorem for complex orbifolds.\n\nDefinition 2.4. A complex orbifold of complex dimension d is a singular complex space whose singularities are locally isomorphic to quotient singularities C d / G , for finite sub- groups G ⊂ Gl ( d, C ) .\n\nDefinition 2.5. A differential form on a complex orbifold Z is defined locally at z ∈ Z as a G -invariant differential form on C d where G ⊂ Gl ( d, C ) and Z is locally isomorphic to d\n\nRoughly speaking the local geometry of orbifolds reduces to local G -invariant geometry.\n\nWe have a complex of differential forms ( A ● ( Z ) , d ) and a double complex ( A ● , ● ( Z ) , ∂, ¯ ∂ ) of bigraded differential forms which define the de Rham and the Dolbeault cohomology groups (for a fixed p ∈ N ) respectively:\n\n(1,1)-Lefschetz theorem for projective toric orbifolds\n\nDefinition 3.1. A subvariety X ⊂ P d Σ is quasi-smooth if V ( I X ) ⊂ A #Σ ( 1 ) is smooth outside\n\nExample 3.2 . Quasi-smooth hypersurfaces or more generally quasi-smooth intersection sub-\n\nExample 3.2 . Quasi-smooth hypersurfaces or more generally quasi-smooth intersection sub- varieties are quasi-smooth subvarieties (see [2] | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-15 | intersection sub- varieties are quasi-smooth subvarieties (see [2] or [7] for more details).\n\nRemark 3.3 . Quasi-smooth subvarieties are suborbifolds of P d Σ in the sense of Satake in [8]. Intuitively speaking they are subvarieties whose only singularities come from the ambient\n\nProof. From the exponential short exact sequence\n\nwe have a long exact sequence in cohomology\n\nH 1 (O ∗ X ) → H 2 ( X, Z ) → H 2 (O X ) ≃ H 0 , 2 ( X )\n\nwhere the last isomorphisms is due to Steenbrink in [9]. Now, it is enough to prove the commutativity of the next diagram\n\nwhere the last isomorphisms is due to Steenbrink in [9]. Now,\n\nH 2 ( X, Z ) / / H 2 ( X, O X ) ≃ Dolbeault H 2 ( X, C ) deRham ≃ H 2 dR ( X, C ) / / H 0 , 2 ¯ ∂ ( X )\n\nof the proof follows as the ( 1 , 1 ) -Lefschetz theorem in [6].\n\nRemark 3.5 . For k = 1 and P d Σ as the projective space, we recover the classical ( 1 , 1 ) - Lefschetz theorem.\n\nBy the Hard Lefschetz Theorem for projective orbifolds (see [11] for details) we\n\nBy the Hard Lefschetz Theorem for projective orbifolds (see [11] for details) we get an | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-16 | Theorem for projective orbifolds (see [11] for details) we get an isomorphism of cohomologies :\n\ngiven by the Lefschetz morphism and since it is a morphism of Hodge structures, we have:\n\nH 1 , 1 ( X, Q ) ≃ H dim X − 1 , dim X − 1 ( X, Q )\n\nCorollary 3.6. If the dimension of X is 1 , 2 or 3 . The Hodge conjecture holds on X\n\nProof. If the dim C X = 1 the result is clear by the Hard Lefschetz theorem for projective orbifolds. The dimension 2 and 3 cases are covered by Theorem 3.5 and the Hard Lefschetz.\n\nCayley trick and Cayley proposition\n\nThe Cayley trick is a way to associate to a quasi-smooth intersection subvariety a quasi- smooth hypersurface. Let L 1 , . . . , L s be line bundles on P d Σ and let π ∶ P ( E ) → P d Σ be the projective space bundle associated to the vector bundle E = L 1 ⊕ ⋯ ⊕ L s . It is known that P ( E ) is a ( d + s − 1 ) -dimensional simplicial toric variety whose fan depends on the degrees of the line bundles and the fan Σ. Furthermore, if the Cox ring, without considering the grading, of P d Σ is C [ x 1 , . . . , x m ] then the Cox ring of P ( E ) is\n\nMoreover for X a quasi-smooth intersection | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-17 | ( E ) is\n\nMoreover for X a quasi-smooth intersection subvariety cut off by f 1 , . . . , f s with deg ( f i ) = [ L i ] we relate the hypersurface Y cut off by F = y 1 f 1 + ⋅ ⋅ ⋅ + y s f s which turns out to be quasi-smooth. For more details see Section 2 in [7].\n\nWe will denote P ( E ) as P d + s − 1 Σ ,X to keep track of its relation with X and P d Σ .\n\nThe following is a key remark.\n\nRemark 4.1 . There is a morphism ι ∶ X → Y ⊂ P d + s − 1 Σ ,X . Moreover every point z ∶ = ( x, y ) ∈ Y with y ≠ 0 has a preimage. Hence for any subvariety W = V ( I W ) ⊂ X ⊂ P d Σ there exists W ′ ⊂ Y ⊂ P d + s − 1 Σ ,X such that π ( W ′ ) = W , i.e., W ′ = { z = ( x, y ) ∣ x ∈ W } .\n\nFor X ⊂ P d Σ a quasi-smooth intersection variety the morphism in cohomology induced by the inclusion i ∗ ∶ H d − s ( P d Σ , C ) → H d − s ( X, C ) is injective by Proposition 1.4 in [7].\n\nDefinition 4.2. The primitive cohomology of H d − s prim ( X ) is the quotient H d − s ( X, C | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-18 | d − s prim ( X ) is the quotient H d − s ( X, C )/ i ∗ ( H d − s ( P d Σ , C )) and H d − s prim ( X, Q ) with rational coefficients.\n\nH d − s ( P d Σ , C ) and H d − s ( X, C ) have pure Hodge structures, and the morphism i ∗ is com- patible with them, so that H d − s prim ( X ) gets a pure Hodge structure.\n\nThe next Proposition is the Cayley proposition.\n\nProposition 4.3. [Proposition 2.3 in [3] ] Let X = X 1 ∩⋅ ⋅ ⋅∩ X s be a quasi-smooth intersec- tion subvariety in P d Σ cut off by homogeneous polynomials f 1 . . . f s . Then for p ≠ d + s − 1 2 , d + s − 3 2\n\nRemark 4.5 . The above isomorphisms are also true with rational coefficients since H ● ( X, C ) = H ● ( X, Q ) ⊗ Q C . See the beginning of Section 7.1 in [10] for more details.\n\nTheorem 5.1. Let Y = { F = y 1 f 1 + ⋯ + y k f k = 0 } ⊂ P 2 k + 1 Σ ,X be the quasi-smooth hypersurface associated to the quasi-smooth intersection surface X = X f 1 ∩ ⋅ ⋅ ⋅ ∩ X f k ⊂ P k + 2 Σ . Then on Y the Hodge conjecture holds.\n\nthe Hodge conjecture | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-19 | Y the Hodge conjecture holds.\n\nthe Hodge conjecture holds.\n\nProof. If H k,k prim ( X, Q ) = 0 we are done. So let us assume H k,k prim ( X, Q ) ≠ 0. By the Cayley proposition H k,k prim ( Y, Q ) ≃ H 1 , 1 prim ( X, Q ) and by the ( 1 , 1 ) -Lefschetz theorem for projective\n\ntoric orbifolds there is a non-zero algebraic basis λ C 1 , . . . , λ C n with rational coefficients of H 1 , 1 prim ( X, Q ) , that is, there are n ∶ = h 1 , 1 prim ( X, Q ) algebraic curves C 1 , . . . , C n in X such that under the Poincar´e duality the class in homology [ C i ] goes to λ C i , [ C i ] ↦ λ C i . Recall that the Cox ring of P k + 2 is contained in the Cox ring of P 2 k + 1 Σ ,X without considering the grading. Considering the grading we have that if α ∈ Cl ( P k + 2 Σ ) then ( α, 0 ) ∈ Cl ( P 2 k + 1 Σ ,X ) . So the polynomials defining C i ⊂ P k + 2 Σ can be interpreted in P 2 k + 1 X, Σ but with different degree. Moreover, by Remark 4.1 each C i is contained in Y = { F = y 1 f 1 + ⋯ + y k f k = 0 } | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-20 | Y = { F = y 1 f 1 + ⋯ + y k f k = 0 } and\n\nfurthermore it has codimension k .\n\nClaim: { C i } ni = 1 is a basis of prim ( ) . It is enough to prove that λ C i is different from zero in H k,k prim ( Y, Q ) or equivalently that the cohomology classes { λ C i } ni = 1 do not come from the ambient space. By contradiction, let us assume that there exists a j and C ⊂ P 2 k + 1 Σ ,X such that λ C ∈ H k,k ( P 2 k + 1 Σ ,X , Q ) with i ∗ ( λ C ) = λ C j or in terms of homology there exists a ( k + 2 ) -dimensional algebraic subvariety V ⊂ P 2 k + 1 Σ ,X such that V ∩ Y = C j so they are equal as a homology class of P 2 k + 1 Σ ,X ,i.e., [ V ∩ Y ] = [ C j ] . It is easy to check that π ( V ) ∩ X = C j as a subvariety of P k + 2 Σ where π ∶ ( x, y ) ↦ x . Hence [ π ( V ) ∩ X ] = [ C j ] which is equivalent to say that λ C j comes from P k + 2 Σ which contradicts the choice of [ C j ] .\n\nRemark 5.2 . Into the proof of the previous theorem, the key fact was that on X the Hodge conjecture holds and we translate it to Y by contradiction. So, using an analogous argument we | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-21 | and we translate it to Y by contradiction. So, using an analogous argument we have:\n\nargument we have:\n\nProposition 5.3. Let Y = { F = y 1 f s +⋯+ y s f s = 0 } ⊂ P 2 k + 1 Σ ,X be the quasi-smooth hypersurface associated to a quasi-smooth intersection subvariety X = X f 1 ∩ ⋅ ⋅ ⋅ ∩ X f s ⊂ P d Σ such that d + s = 2 ( k + 1 ) . If the Hodge conjecture holds on X then it holds as well on Y .\n\nCorollary 5.4. If the dimension of Y is 2 s − 1 , 2 s or 2 s + 1 then the Hodge conjecture holds on Y .\n\nProof. By Proposition 5.3 and Corollary 3.6.\n\n[\n\n] Angella, D. Cohomologies of certain orbifolds. Journal of Geometry and Physics\n\n(\n\n),\n\n–\n\n[\n\n] Batyrev, V. V., and Cox, D. A. On the Hodge structure of projective hypersur- faces in toric varieties. Duke Mathematical Journal\n\n,\n\n(Aug\n\n). [\n\n] Bruzzo, U., and Montoya, W. On the Hodge conjecture for quasi-smooth in- tersections in toric varieties. S˜ao Paulo J. Math. Sci. Special Section: Geometry in Algebra and Algebra in Geometry | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-22 | Sci. Special Section: Geometry in Algebra and Algebra in Geometry (\n\n). [\n\n] Caramello Jr, F. C. Introduction to orbifolds. a\n\niv:\n\nv\n\n(\n\n). [\n\n] Cox, D., Little, J., and Schenck, H. Toric varieties, vol.\n\nAmerican Math- ematical Soc.,\n\n[\n\n] Griffiths, P., and Harris, J. Principles of Algebraic Geometry. John Wiley & Sons, Ltd,\n\n[\n\n] Mavlyutov, A. R. Cohomology of complete intersections in toric varieties. Pub- lished in Pacific J. of Math.\n\nNo.\n\n(\n\n),\n\n–\n\n[\n\n] Satake, I. On a Generalization of the Notion of Manifold. Proceedings of the National Academy of Sciences of the United States of America\n\n,\n\n(\n\n),\n\n–\n\n[\n\n] Steenbrink, J. H. M. Intersection form for quasi-homogeneous singularities. Com- positio Mathematica\n\n,\n\n(\n\n),\n\n–\n\n[\n\n] Voisin, C. Hodge Theory and Complex Algebraic Geometry I, vol.\n\nof Cambridge Studies in Advanced Mathematics . Cambridge University | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-23 | I, vol.\n\nof Cambridge Studies in Advanced Mathematics . Cambridge University Press,\n\n[\n\n] Wang, Z. Z., and Zaffran, D. A remark on the Hard Lefschetz theorem for K¨ahler orbifolds. Proceedings of the American Mathematical Society\n\n,\n\n(Aug\n\n).\n\n[2] Batyrev, V. V., and Cox, D. A. On the Hodge structure of projective hypersur- faces in toric varieties. Duke Mathematical Journal 75, 2 (Aug 1994).\n\n[\n\n] Bruzzo, U., and Montoya, W. On the Hodge conjecture for quasi-smooth in- tersections in toric varieties. S˜ao Paulo J. Math. Sci. Special Section: Geometry in Algebra and Algebra in Geometry (\n\n).\n\n[3] Bruzzo, U., and Montoya, W. On the Hodge conjecture for quasi-smooth in- tersections in toric varieties. S˜ao Paulo J. Math. Sci. Special Section: Geometry in Algebra and Algebra in Geometry (2021).\n\nA. R. Cohomology of complete intersections in toric varieties. Pub-', lookup_str='', metadata={'source': '/var/folders/ph/hhm7_zyx4l13k3v8z02dwp1w0000gn/T/tmpgq0ckaja/online_file.pdf'}, lookup_index=0)] | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-24 | Using PDFMiner#
from langchain.document_loaders import PDFMinerLoader
loader = PDFMinerLoader("example_data/layout-parser-paper.pdf")
data = loader.load()
Using PDFMiner to generate HTML text#
This can be helpful for chunking texts semantically into sections as the output html content can be parsed via BeautifulSoup to get more structured and rich information about font size, page numbers, pdf headers/footers, etc.
from langchain.document_loaders import PDFMinerPDFasHTMLLoader
loader = PDFMinerPDFasHTMLLoader("example_data/layout-parser-paper.pdf")
data = loader.load()[0] # entire pdf is loaded as a single Document
from bs4 import BeautifulSoup
soup = BeautifulSoup(data.page_content,'html.parser')
content = soup.find_all('div')
import re
cur_fs = None
cur_text = ''
snippets = [] # first collect all snippets that have the same font size
for c in content:
sp = c.find('span')
if not sp:
continue
st = sp.get('style')
if not st:
continue
fs = re.findall('font-size:(\d+)px',st)
if not fs:
continue
fs = int(fs[0])
if not cur_fs:
cur_fs = fs
if fs == cur_fs:
cur_text += c.text
else:
snippets.append((cur_text,cur_fs))
cur_fs = fs
cur_text = c.text | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-25 | cur_fs = fs
cur_text = c.text
snippets.append((cur_text,cur_fs))
# Note: The above logic is very straightforward. One can also add more strategies such as removing duplicate snippets (as
# headers/footers in a PDF appear on multiple pages so if we find duplicatess safe to assume that it is redundant info)
from langchain.docstore.document import Document
cur_idx = -1
semantic_snippets = []
# Assumption: headings have higher font size than their respective content
for s in snippets:
# if current snippet's font size > previous section's heading => it is a new heading
if not semantic_snippets or s[1] > semantic_snippets[cur_idx].metadata['heading_font']:
metadata={'heading':s[0], 'content_font': 0, 'heading_font': s[1]}
metadata.update(data.metadata)
semantic_snippets.append(Document(page_content='',metadata=metadata))
cur_idx += 1
continue
# if current snippet's font size <= previous section's content => content belongs to the same section (one can also create
# a tree like structure for sub sections if needed but that may require some more thinking and may be data specific)
if not semantic_snippets[cur_idx].metadata['content_font'] or s[1] <= semantic_snippets[cur_idx].metadata['content_font']: | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-26 | semantic_snippets[cur_idx].page_content += s[0]
semantic_snippets[cur_idx].metadata['content_font'] = max(s[1], semantic_snippets[cur_idx].metadata['content_font'])
continue
# if current snippet's font size > previous section's content but less tha previous section's heading than also make a new
# section (e.g. title of a pdf will have the highest font size but we don't want it to subsume all sections)
metadata={'heading':s[0], 'content_font': 0, 'heading_font': s[1]}
metadata.update(data.metadata)
semantic_snippets.append(Document(page_content='',metadata=metadata))
cur_idx += 1
semantic_snippets[4] | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-27 | Document(page_content='Recently, various DL models and datasets have been developed for layout analysis\ntasks. The dhSegment [22] utilizes fully convolutional networks [20] for segmen-\ntation tasks on historical documents. Object detection-based methods like Faster\nR-CNN [28] and Mask R-CNN [12] are used for identifying document elements [38]\nand detecting tables [30, 26]. Most recently, Graph Neural Networks [29] have also\nbeen used in table detection [27]. However, these models are usually implemented\nindividually and there is no unified framework to load and use such models.\nThere has been a surge of interest in creating open-source tools for document\nimage processing: a search of document image analysis in Github leads to 5M\nrelevant code pieces 6; yet most of them rely on traditional rule-based methods\nor provide limited functionalities. The closest prior research to our work is the\nOCR-D project7, which also tries to build a complete toolkit for DIA. However,\nsimilar to the platform developed by Neudecker et al. [21], it is designed for\nanalyzing historical documents, and provides no supports for recent DL models.\nThe DocumentLayoutAnalysis project8 focuses on processing born-digital PDF\ndocuments via analyzing the stored PDF data. Repositories like DeepLayout9\nand Detectron2-PubLayNet10 are individual deep learning models trained on\nlayout analysis datasets without support for the full DIA pipeline. The Document\nAnalysis and Exploitation (DAE) platform [15] and the DeepDIVA project | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-28 | and Exploitation (DAE) platform [15] and the DeepDIVA project [2]\naim to improve the reproducibility of DIA methods (or DL models), yet they\nare not actively maintained. OCR engines like Tesseract [14], easyOCR11 and\npaddleOCR12 usually do not come with comprehensive functionalities for other\nDIA tasks like layout analysis.\nRecent years have also seen numerous efforts to create libraries for promoting\nreproducibility and reusability in the field of DL. Libraries like Dectectron2 [35],\n6 The number shown is obtained by specifying the search type as ‘code’.\n7 https://ocr-d.de/en/about\n8 https://github.com/BobLd/DocumentLayoutAnalysis\n9 https://github.com/leonlulu/DeepLayout\n10 https://github.com/hpanwar08/detectron2\n11 https://github.com/JaidedAI/EasyOCR\n12 https://github.com/PaddlePaddle/PaddleOCR\n4\nZ. Shen et al.\nFig. 1: The overall architecture of LayoutParser. For an input document image,\nthe core LayoutParser library provides a set of off-the-shelf tools for layout\ndetection, OCR, visualization, and storage, backed by a carefully designed layout\ndata structure. LayoutParser also supports high level customization via efficient\nlayout annotation and model training functions. These improve model accuracy\non the target samples. The community platform enables the easy sharing of DIA\nmodels and whole | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-29 | target samples. The community platform enables the easy sharing of DIA\nmodels and whole digitization pipelines to promote reusability and reproducibility.\nA collection of detailed documentation, tutorials and exemplar projects make\nLayoutParser easy to learn and use.\nAllenNLP [8] and transformers [34] have provided the community with complete\nDL-based support for developing and deploying models for general computer\nvision and natural language processing problems. LayoutParser, on the other\nhand, specializes specifically in DIA tasks. LayoutParser is also equipped with a\ncommunity platform inspired by established model hubs such as Torch Hub [23]\nand TensorFlow Hub [1]. It enables the sharing of pretrained models as well as\nfull document processing pipelines that are unique to DIA tasks.\nThere have been a variety of document data collections to facilitate the\ndevelopment of DL models. Some examples include PRImA [3](magazine layouts),\nPubLayNet [38](academic paper layouts), Table Bank [18](tables in academic\npapers), Newspaper Navigator Dataset [16, 17](newspaper figure layouts) and\nHJDataset [31](historical Japanese document layouts). A spectrum of models\ntrained on these datasets are currently available in the LayoutParser model zoo\nto support different use cases.\n', metadata={'heading': '2 Related Work\n', 'content_font': 9, 'heading_font': 11, 'source': 'example_data/layout-parser-paper.pdf'}) | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-30 | Using PyMuPDF#
This is the fastest of the PDF parsing options, and contains detailed metadata about the PDF and its pages, as well as returns one document per page.
from langchain.document_loaders import PyMuPDFLoader
loader = PyMuPDFLoader("example_data/layout-parser-paper.pdf")
data = loader.load()
data[0] | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-31 | Document(page_content='LayoutParser: A Unified Toolkit for Deep\nLearning Based Document Image Analysis\nZejiang Shen1 (�), Ruochen Zhang2, Melissa Dell3, Benjamin Charles Germain\nLee4, Jacob Carlson3, and Weining Li5\n1 Allen Institute for AI\[email protected]\n2 Brown University\nruochen [email protected]\n3 Harvard University\n{melissadell,jacob carlson}@fas.harvard.edu\n4 University of Washington\[email protected]\n5 University of Waterloo\[email protected]\nAbstract. Recent advances in document image analysis (DIA) have been\nprimarily driven by the application of neural networks. Ideally, research\noutcomes could be easily deployed in production and extended for further\ninvestigation. However, various factors like loosely organized codebases\nand sophisticated model configurations complicate the easy reuse of im-\nportant innovations by a wide audience. Though there have been on-going\nefforts to improve reusability and simplify deep learning (DL) model\ndevelopment in disciplines like natural language processing and computer\nvision, none of them are optimized for challenges in the domain of DIA.\nThis represents a major gap in the existing toolkit, as DIA is central to\nacademic research across a wide range of disciplines in the social sciences\nand humanities. This paper introduces LayoutParser, an open-source\nlibrary for streamlining the usage of DL in DIA research | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-32 | open-source\nlibrary for streamlining the usage of DL in DIA research and applica-\ntions. The core LayoutParser library comes with a set of simple and\nintuitive interfaces for applying and customizing DL models for layout de-\ntection, character recognition, and many other document processing tasks.\nTo promote extensibility, LayoutParser also incorporates a community\nplatform for sharing both pre-trained models and full document digiti-\nzation pipelines. We demonstrate that LayoutParser is helpful for both\nlightweight and large-scale digitization pipelines in real-word use cases.\nThe library is publicly available at https://layout-parser.github.io.\nKeywords: Document Image Analysis · Deep Learning · Layout Analysis\n· Character Recognition · Open Source library · Toolkit.\n1\nIntroduction\nDeep Learning(DL)-based approaches are the state-of-the-art for a wide range of\ndocument image analysis (DIA) tasks including document image classification [11,\narXiv:2103.15348v2 [cs.CV] 21 Jun 2021\n', lookup_str='', metadata={'file_path': 'example_data/layout-parser-paper.pdf', 'page_number': 1, 'total_pages': 16, 'format': 'PDF 1.5', 'title': '', 'author': '', 'subject': '', 'keywords': '', 'creator': 'LaTeX with hyperref', 'producer': 'pdfTeX-1.40.21', | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-33 | hyperref', 'producer': 'pdfTeX-1.40.21', 'creationDate': 'D:20210622012710Z', 'modDate': 'D:20210622012710Z', 'trapped': '', 'encryption': None}, lookup_index=0) | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7b0dfe8ade09-34 | Additionally, you can pass along any of the options from the PyMuPDF documentation as keyword arguments in the load call, and it will be pass along to the get_text() call.
previous
Obsidian
next
PowerPoint
Contents
Using PyPDF
Using Unstructured
Retain Elements
Fetching remote PDFs using Unstructured
Using PDFMiner
Using PDFMiner to generate HTML text
Using PyMuPDF
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Apr 26, 2023. | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/pdf.html |
7e3e629ee4a0-0 | .ipynb
.pdf
CoNLL-U
CoNLL-U#
This is an example of how to load a file in CoNLL-U format. The whole file is treated as one document. The example data (conllu.conllu) is based on one of the standard UD/CoNLL-U examples.
from langchain.document_loaders import CoNLLULoader
loader = CoNLLULoader("example_data/conllu.conllu")
document = loader.load()
document
previous
Document Loaders
next
Airbyte JSON
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Apr 26, 2023. | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/CoNLL-U.html |
79bd01e7a10e-0 | .ipynb
.pdf
Markdown
Contents
Retain Elements
Markdown#
This covers how to load markdown documents into a document format that we can use downstream.
from langchain.document_loaders import UnstructuredMarkdownLoader
loader = UnstructuredMarkdownLoader("../../../../README.md")
data = loader.load()
data | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/markdown.html |
79bd01e7a10e-1 | [Document(page_content="ð\x9f¦\x9cï¸\x8fð\x9f”\x97 LangChain\n\nâ\x9a¡ Building applications with LLMs through composability â\x9a¡\n\nProduction Support: As you move your LangChains into production, we'd love to offer more comprehensive support.\nPlease fill out this form and we'll set up a dedicated support Slack channel.\n\nQuick Install\n\npip install langchain\n\nð\x9f¤” What is this?\n\nLarge language models (LLMs) are emerging as a transformative technology, enabling\ndevelopers to build applications that they previously could not.\nBut using these LLMs in isolation is often not enough to\ncreate a truly powerful app - the real power comes when you can combine them with other sources of computation or knowledge.\n\nThis library is aimed at assisting in the development of those types of applications. Common examples of these types of applications include:\n\nâ\x9d“ Question Answering over specific documents\n\nDocumentation\n\nEnd-to-end Example: Question Answering over Notion Database\n\nð\x9f’¬ Chatbots\n\nDocumentation\n\nEnd-to-end Example: Chat-LangChain\n\nð\x9f¤\x96 Agents\n\nDocumentation\n\nEnd-to-end Example: GPT+WolframAlpha\n\nð\x9f“\x96 Documentation\n\nPlease see here for full documentation | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/markdown.html |
79bd01e7a10e-2 | Documentation\n\nPlease see here for full documentation on:\n\nGetting started (installation, setting up the environment, simple examples)\n\nHow-To examples (demos, integrations, helper functions)\n\nReference (full API docs)\n Resources (high-level explanation of core concepts)\n\nð\x9f\x9a\x80 What can this help with?\n\nThere are six main areas that LangChain is designed to help with.\nThese are, in increasing order of complexity:\n\nð\x9f“\x83 LLMs and Prompts:\n\nThis includes prompt management, prompt optimization, generic interface for all LLMs, and common utilities for working with LLMs.\n\nð\x9f”\x97 Chains:\n\nChains go beyond just a single LLM call, and are sequences of calls (whether to an LLM or a different utility). LangChain provides a standard interface for chains, lots of integrations with other tools, and end-to-end chains for common applications.\n\nð\x9f“\x9a Data Augmented Generation:\n\nData Augmented Generation involves specific types of chains that first interact with an external datasource to fetch data to use in the generation step. Examples of this include summarization of long pieces of text and question/answering over specific data sources.\n\nð\x9f¤\x96 Agents:\n\nAgents involve an LLM making decisions about which Actions to take, taking that Action, seeing an Observation, and repeating that until | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/markdown.html |
79bd01e7a10e-3 | which Actions to take, taking that Action, seeing an Observation, and repeating that until done. LangChain provides a standard interface for agents, a selection of agents to choose from, and examples of end to end agents.\n\nð\x9f§\xa0 Memory:\n\nMemory is the concept of persisting state between calls of a chain/agent. LangChain provides a standard interface for memory, a collection of memory implementations, and examples of chains/agents that use memory.\n\nð\x9f§\x90 Evaluation:\n\n[BETA] Generative models are notoriously hard to evaluate with traditional metrics. One new way of evaluating them is using language models themselves to do the evaluation. LangChain provides some prompts/chains for assisting in this.\n\nFor more information on these concepts, please see our full documentation.\n\nð\x9f’\x81 Contributing\n\nAs an open source project in a rapidly developing field, we are extremely open to contributions, whether it be in the form of a new feature, improved infra, or better documentation.\n\nFor detailed information on how to contribute, see here.", lookup_str='', metadata={'source': '../../../../README.md'}, lookup_index=0)] | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/markdown.html |
79bd01e7a10e-4 | Retain Elements#
Under the hood, Unstructured creates different “elements” for different chunks of text. By default we combine those together, but you can easily keep that separation by specifying mode="elements".
loader = UnstructuredMarkdownLoader("../../../../README.md", mode="elements")
data = loader.load()
data[0]
Document(page_content='ð\x9f¦\x9cï¸\x8fð\x9f”\x97 LangChain', lookup_str='', metadata={'source': '../../../../README.md', 'page_number': 1, 'category': 'UncategorizedText'}, lookup_index=0)
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Retain Elements
By Harrison Chase
© Copyright 2023, Harrison Chase.
Last updated on Apr 26, 2023. | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/markdown.html |
056f81721b80-0 | .ipynb
.pdf
Image captions
Contents
Prepare a list of image urls from Wikimedia
Create the loader
Create the index
Query
Image captions#
This notebook shows how to use the ImageCaptionLoader tutorial to generate a query-able index of image captions
from langchain.document_loaders import ImageCaptionLoader
Prepare a list of image urls from Wikimedia#
list_image_urls = [
'https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Hyla_japonica_sep01.jpg/260px-Hyla_japonica_sep01.jpg',
'https://upload.wikimedia.org/wikipedia/commons/thumb/7/71/Tibur%C3%B3n_azul_%28Prionace_glauca%29%2C_canal_Fayal-Pico%2C_islas_Azores%2C_Portugal%2C_2020-07-27%2C_DD_14.jpg/270px-Tibur%C3%B3n_azul_%28Prionace_glauca%29%2C_canal_Fayal-Pico%2C_islas_Azores%2C_Portugal%2C_2020-07-27%2C_DD_14.jpg',
'https://upload.wikimedia.org/wikipedia/commons/thumb/2/21/Thure_de_Thulstrup_-_Battle_of_Shiloh.jpg/251px-Thure_de_Thulstrup_-_Battle_of_Shiloh.jpg', | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/image_captions.html |
056f81721b80-1 | 'https://upload.wikimedia.org/wikipedia/commons/thumb/2/21/Passion_fruits_-_whole_and_halved.jpg/270px-Passion_fruits_-_whole_and_halved.jpg',
'https://upload.wikimedia.org/wikipedia/commons/thumb/5/5e/Messier83_-_Heic1403a.jpg/277px-Messier83_-_Heic1403a.jpg',
'https://upload.wikimedia.org/wikipedia/commons/thumb/b/b6/2022-01-22_Men%27s_World_Cup_at_2021-22_St._Moritz%E2%80%93Celerina_Luge_World_Cup_and_European_Championships_by_Sandro_Halank%E2%80%93257.jpg/288px-2022-01-22_Men%27s_World_Cup_at_2021-22_St._Moritz%E2%80%93Celerina_Luge_World_Cup_and_European_Championships_by_Sandro_Halank%E2%80%93257.jpg',
'https://upload.wikimedia.org/wikipedia/commons/thumb/9/99/Wiesen_Pippau_%28Crepis_biennis%29-20220624-RM-123950.jpg/224px-Wiesen_Pippau_%28Crepis_biennis%29-20220624-RM-123950.jpg',
]
Create the loader#
loader = ImageCaptionLoader(path_images=list_image_urls)
list_docs = loader.load()
list_docs | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/image_captions.html |
056f81721b80-2 | list_docs = loader.load()
list_docs
/Users/saitosean/dev/langchain/.venv/lib/python3.10/site-packages/transformers/generation/utils.py:1313: UserWarning: Using `max_length`'s default (20) to control the generation length. This behaviour is deprecated and will be removed from the config in v5 of Transformers -- we recommend using `max_new_tokens` to control the maximum length of the generation.
warnings.warn(
[Document(page_content='an image of a frog on a flower [SEP]', metadata={'image_path': 'https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Hyla_japonica_sep01.jpg/260px-Hyla_japonica_sep01.jpg'}),
Document(page_content='an image of a shark swimming in the ocean [SEP]', metadata={'image_path': 'https://upload.wikimedia.org/wikipedia/commons/thumb/7/71/Tibur%C3%B3n_azul_%28Prionace_glauca%29%2C_canal_Fayal-Pico%2C_islas_Azores%2C_Portugal%2C_2020-07-27%2C_DD_14.jpg/270px-Tibur%C3%B3n_azul_%28Prionace_glauca%29%2C_canal_Fayal-Pico%2C_islas_Azores%2C_Portugal%2C_2020-07-27%2C_DD_14.jpg'}), | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/image_captions.html |
056f81721b80-3 | Document(page_content='an image of a painting of a battle scene [SEP]', metadata={'image_path': 'https://upload.wikimedia.org/wikipedia/commons/thumb/2/21/Thure_de_Thulstrup_-_Battle_of_Shiloh.jpg/251px-Thure_de_Thulstrup_-_Battle_of_Shiloh.jpg'}),
Document(page_content='an image of a passion fruit and a half cut passion [SEP]', metadata={'image_path': 'https://upload.wikimedia.org/wikipedia/commons/thumb/2/21/Passion_fruits_-_whole_and_halved.jpg/270px-Passion_fruits_-_whole_and_halved.jpg'}),
Document(page_content='an image of the spiral galaxy [SEP]', metadata={'image_path': 'https://upload.wikimedia.org/wikipedia/commons/thumb/5/5e/Messier83_-_Heic1403a.jpg/277px-Messier83_-_Heic1403a.jpg'}), | /content/https://python.langchain.com/en/latest/modules/indexes/document_loaders/examples/image_captions.html |
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