Docling
Docling 将 PDF、DOCX、PPTX、HTML 和其他格式解析为包含文档布局、表格等的丰富统一表示，使它们可用于像 RAG 这样的生成式 AI 工作流。
此集成通过 DoclingLoader 文档加载器提供 Docling 的功能。
概述
所提供的 DoclingLoader 组件使您能够
- 轻松快速地在您的 LLM 应用程序中使用各种文档类型，以及
- 利用 Docling 的丰富格式进行高级的、文档原生的基础构建。
DoclingLoader 支持两种不同的导出模式
ExportType.DOC_CHUNKS（默认）：如果您希望将每个输入文档分块，然后将每个单独的块作为单独的 LangChain 文档下游捕获，或者ExportType.MARKDOWN：如果您希望将每个输入文档作为单独的 LangChain 文档捕获
此示例允许通过参数 EXPORT_TYPE 探索两种模式；根据设置的值，示例管道将相应地进行设置。
设置
%pip install -qU langchain-docling
Note: you may need to restart the kernel to use updated packages.
为了获得最佳转换速度，请在可用时使用 GPU 加速；例如，如果在 Colab 上运行，请使用启用 GPU 的运行时。
初始化
基本初始化如下所示
from langchain_docling import DoclingLoader
FILE_PATH = "https://arxiv.org/pdf/2408.09869"
loader = DoclingLoader(file_path=FILE_PATH)
对于高级用法，DoclingLoader 具有以下参数
file_path：源文件，可以是单个字符串（URL 或本地文件）或其可迭代对象converter(可选)：要使用的任何特定 Docling 转换器实例convert_kwargs(可选)：转换执行的任何特定 kwargs 参数export_type(可选)：要使用的导出模式：ExportType.DOC_CHUNKS（默认）或ExportType.MARKDOWNmd_export_kwargs(可选)：任何特定的 Markdown 导出 kwargs 参数（适用于 Markdown 模式）chunker(可选)：要使用的任何特定 Docling 分块器实例（适用于文档分块模式）meta_extractor(可选)：要使用的任何特定元数据提取器
加载
docs = loader.load()
Token indices sequence length is longer than the specified maximum sequence length for this model (1041 > 512). Running this sequence through the model will result in indexing errors
注意：在这种情况下，可以忽略消息
"Token indices sequence length is longer than the specified maximum sequence length..."— 更多详细信息请参阅此处。
检查一些示例文档
for d in docs[:3]:
print(f"- {d.page_content=}")
- d.page_content='arXiv:2408.09869v5 [cs.CL] 9 Dec 2024'
- d.page_content='Docling Technical Report\nVersion 1.0\nChristoph Auer Maksym Lysak Ahmed Nassar Michele Dolfi Nikolaos Livathinos Panos Vagenas Cesar Berrospi Ramis Matteo Omenetti Fabian Lindlbauer Kasper Dinkla Lokesh Mishra Yusik Kim Shubham Gupta Rafael Teixeira de Lima Valery Weber Lucas Morin Ingmar Meijer Viktor Kuropiatnyk Peter W. J. Staar\nAI4K Group, IBM Research R¨uschlikon, Switzerland'
- d.page_content='Abstract\nThis technical report introduces Docling , an easy to use, self-contained, MITlicensed open-source package for PDF document conversion. It is powered by state-of-the-art specialized AI models for layout analysis (DocLayNet) and table structure recognition (TableFormer), and runs efficiently on commodity hardware in a small resource budget. The code interface allows for easy extensibility and addition of new features and models.'
延迟加载
文档也可以延迟加载
doc_iter = loader.lazy_load()
for doc in doc_iter:
pass # you can operate on `doc` here
端到端示例
import os
# https://github.com/huggingface/transformers/issues/5486:
os.environ["TOKENIZERS_PARALLELISM"] = "false"
- 以下示例管道使用 HuggingFace 的推理 API；为了增加 LLM 配额，可以通过环境变量
HF_TOKEN提供令牌。- 此管道的依赖项可以按如下所示安装（
--no-warn-conflicts适用于 Colab 预填充的 Python 环境；对于更严格的用法，您可以随意删除）
%pip install -q --progress-bar off --no-warn-conflicts langchain-core langchain-huggingface langchain_milvus langchain python-dotenv
Note: you may need to restart the kernel to use updated packages.
定义管道参数
from pathlib import Path
from tempfile import mkdtemp
from dotenv import load_dotenv
from langchain_core.prompts import PromptTemplate
from langchain_docling.loader import ExportType
def _get_env_from_colab_or_os(key):
try:
from google.colab import userdata
try:
return userdata.get(key)
except userdata.SecretNotFoundError:
pass
except ImportError:
pass
return os.getenv(key)
load_dotenv()
HF_TOKEN = _get_env_from_colab_or_os("HF_TOKEN")
FILE_PATH = ["https://arxiv.org/pdf/2408.09869"] # Docling Technical Report
EMBED_MODEL_ID = "sentence-transformers/all-MiniLM-L6-v2"
GEN_MODEL_ID = "mistralai/Mixtral-8x7B-Instruct-v0.1"
EXPORT_TYPE = ExportType.DOC_CHUNKS
QUESTION = "Which are the main AI models in Docling?"
PROMPT = PromptTemplate.from_template(
"Context information is below.\n---------------------\n{context}\n---------------------\nGiven the context information and not prior knowledge, answer the query.\nQuery: {input}\nAnswer:\n",
)
TOP_K = 3
MILVUS_URI = str(Path(mkdtemp()) / "docling.db")
API 参考：PromptTemplate
现在我们可以实例化加载器并加载文档
from docling.chunking import HybridChunker
from langchain_docling import DoclingLoader
loader = DoclingLoader(
file_path=FILE_PATH,
export_type=EXPORT_TYPE,
chunker=HybridChunker(tokenizer=EMBED_MODEL_ID),
)
docs = loader.load()
Token indices sequence length is longer than the specified maximum sequence length for this model (1041 > 512). Running this sequence through the model will result in indexing errors
确定拆分
if EXPORT_TYPE == ExportType.DOC_CHUNKS:
splits = docs
elif EXPORT_TYPE == ExportType.MARKDOWN:
from langchain_text_splitters import MarkdownHeaderTextSplitter
splitter = MarkdownHeaderTextSplitter(
headers_to_split_on=[
("#", "Header_1"),
("##", "Header_2"),
("###", "Header_3"),
],
)
splits = [split for doc in docs for split in splitter.split_text(doc.page_content)]
else:
raise ValueError(f"Unexpected export type: {EXPORT_TYPE}")
API 参考：MarkdownHeaderTextSplitter
检查一些样本拆分
for d in splits[:3]:
print(f"- {d.page_content=}")
print("...")
- d.page_content='arXiv:2408.09869v5 [cs.CL] 9 Dec 2024'
- d.page_content='Docling Technical Report\nVersion 1.0\nChristoph Auer Maksym Lysak Ahmed Nassar Michele Dolfi Nikolaos Livathinos Panos Vagenas Cesar Berrospi Ramis Matteo Omenetti Fabian Lindlbauer Kasper Dinkla Lokesh Mishra Yusik Kim Shubham Gupta Rafael Teixeira de Lima Valery Weber Lucas Morin Ingmar Meijer Viktor Kuropiatnyk Peter W. J. Staar\nAI4K Group, IBM Research R¨uschlikon, Switzerland'
- d.page_content='Abstract\nThis technical report introduces Docling , an easy to use, self-contained, MITlicensed open-source package for PDF document conversion. It is powered by state-of-the-art specialized AI models for layout analysis (DocLayNet) and table structure recognition (TableFormer), and runs efficiently on commodity hardware in a small resource budget. The code interface allows for easy extensibility and addition of new features and models.'
...
摄取
import json
from pathlib import Path
from tempfile import mkdtemp
from langchain_huggingface.embeddings import HuggingFaceEmbeddings
from langchain_milvus import Milvus
embedding = HuggingFaceEmbeddings(model_name=EMBED_MODEL_ID)
milvus_uri = str(Path(mkdtemp()) / "docling.db") # or set as needed
vectorstore = Milvus.from_documents(
documents=splits,
embedding=embedding,
collection_name="docling_demo",
connection_args={"uri": milvus_uri},
index_params={"index_type": "FLAT"},
drop_old=True,
)
API 参考：HuggingFaceEmbeddings
RAG
from langchain.chains import create_retrieval_chain
from langchain.chains.combine_documents import create_stuff_documents_chain
from langchain_huggingface import HuggingFaceEndpoint
retriever = vectorstore.as_retriever(search_kwargs={"k": TOP_K})
llm = HuggingFaceEndpoint(
repo_id=GEN_MODEL_ID,
huggingfacehub_api_token=HF_TOKEN,
task="text-generation",
)
def clip_text(text, threshold=100):
return f"{text[:threshold]}..." if len(text) > threshold else text
question_answer_chain = create_stuff_documents_chain(llm, PROMPT)
rag_chain = create_retrieval_chain(retriever, question_answer_chain)
resp_dict = rag_chain.invoke({"input": QUESTION})
clipped_answer = clip_text(resp_dict["answer"], threshold=350)
print(f"Question:\n{resp_dict['input']}\n\nAnswer:\n{clipped_answer}")
for i, doc in enumerate(resp_dict["context"]):
print()
print(f"Source {i + 1}:")
print(f" text: {json.dumps(clip_text(doc.page_content, threshold=350))}")
for key in doc.metadata:
if key != "pk":
val = doc.metadata.get(key)
clipped_val = clip_text(val) if isinstance(val, str) else val
print(f" {key}: {clipped_val}")
Question:
Which are the main AI models in Docling?
Answer:
The main AI models in Docling are a layout analysis model, which is an accurate object-detector for page elements, and TableFormer, a state-of-the-art table structure recognition model.
Source 1:
text: "3.2 AI models\nAs part of Docling, we initially release two highly capable AI models to the open-source community, which have been developed and published recently by our team. The first model is a layout analysis model, an accurate object-detector for page elements [13]. The second model is TableFormer [12, 9], a state-of-the-art table structure re..."
dl_meta: {'schema_name': 'docling_core.transforms.chunker.DocMeta', 'version': '1.0.0', 'doc_items': [{'self_ref': '#/texts/50', 'parent': {'$ref': '#/body'}, 'children': [], 'label': 'text', 'prov': [{'page_no': 3, 'bbox': {'l': 108.0, 't': 405.1419982910156, 'r': 504.00299072265625, 'b': 330.7799987792969, 'coord_origin': 'BOTTOMLEFT'}, 'charspan': [0, 608]}]}], 'headings': ['3.2 AI models'], 'origin': {'mimetype': 'application/pdf', 'binary_hash': 11465328351749295394, 'filename': '2408.09869v5.pdf'}}
source: https://arxiv.org/pdf/2408.09869
Source 2:
text: "3 Processing pipeline\nDocling implements a linear pipeline of operations, which execute sequentially on each given document (see Fig. 1). Each document is first parsed by a PDF backend, which retrieves the programmatic text tokens, consisting of string content and its coordinates on the page, and also renders a bitmap image of each page to support ..."
dl_meta: {'schema_name': 'docling_core.transforms.chunker.DocMeta', 'version': '1.0.0', 'doc_items': [{'self_ref': '#/texts/26', 'parent': {'$ref': '#/body'}, 'children': [], 'label': 'text', 'prov': [{'page_no': 2, 'bbox': {'l': 108.0, 't': 273.01800537109375, 'r': 504.00299072265625, 'b': 176.83799743652344, 'coord_origin': 'BOTTOMLEFT'}, 'charspan': [0, 796]}]}], 'headings': ['3 Processing pipeline'], 'origin': {'mimetype': 'application/pdf', 'binary_hash': 11465328351749295394, 'filename': '2408.09869v5.pdf'}}
source: https://arxiv.org/pdf/2408.09869
Source 3:
text: "6 Future work and contributions\nDocling is designed to allow easy extension of the model library and pipelines. In the future, we plan to extend Docling with several more models, such as a figure-classifier model, an equationrecognition model, a code-recognition model and more. This will help improve the quality of conversion for specific types of ..."
dl_meta: {'schema_name': 'docling_core.transforms.chunker.DocMeta', 'version': '1.0.0', 'doc_items': [{'self_ref': '#/texts/76', 'parent': {'$ref': '#/body'}, 'children': [], 'label': 'text', 'prov': [{'page_no': 5, 'bbox': {'l': 108.0, 't': 322.468994140625, 'r': 504.00299072265625, 'b': 259.0169982910156, 'coord_origin': 'BOTTOMLEFT'}, 'charspan': [0, 543]}]}, {'self_ref': '#/texts/77', 'parent': {'$ref': '#/body'}, 'children': [], 'label': 'text', 'prov': [{'page_no': 5, 'bbox': {'l': 108.0, 't': 251.6540069580078, 'r': 504.00299072265625, 'b': 198.99200439453125, 'coord_origin': 'BOTTOMLEFT'}, 'charspan': [0, 402]}]}], 'headings': ['6 Future work and contributions'], 'origin': {'mimetype': 'application/pdf', 'binary_hash': 11465328351749295394, 'filename': '2408.09869v5.pdf'}}
source: https://arxiv.org/pdf/2408.09869
请注意，来源包含丰富的基础信息，包括段落标题（即章节）、页码和精确的边界框。