Docling
Docling 将 PDF、DOCX、PPTX、HTML 及其他格式解析为包含文档布局、表格等在内的丰富统一表示形式，使其适用于 RAG 等生成式 AI 工作流。
此集成通过 DoclingLoader 文档加载器提供 Docling 的功能。
概览
所展示的 DoclingLoader 组件使您能够：
- 轻松快速地在您的大语言模型应用中使用各种文档类型，并
- 利用 Docling 丰富的格式实现高级的、面向文档的原生定位。
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进行分块，然后将每个单独的块作为下游的独立 LangChain 文档进行捕获，或者ExportType.MARKDOWN：如果您希望将每个输入文档捕获为单独的 LangChain 文档
该示例允许通过参数 EXPORT_TYPE 探索两种模式；根据设置的值，示例管道将相应地进行配置。
设置
%pip install -qU langchain-docling
Note: you may need to restart the kernel to use updated packages.
For best conversion speed, use GPU acceleration whenever available; e.g. if running on Colab, use a GPU-enabled runtime.
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：源为单个字符串（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）：用于转换执行的任何特定关键字参数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 导出参数（用于 Markdown 模式）chunker（可选）：要使用的特定 Docling 分块器实例（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
Note: a message saying
"Token indices sequence length is longer than the specified maximum sequence length..."can be ignored in this case — more details here.
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.'
懒加载
文档也可以以惰性方式加载：
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"
- The following example pipeline uses HuggingFace's Inference API; for increased LLM quota, token can be provided via env var
HF_TOKEN.- Dependencies for this pipeline can be installed as shown below (
--no-warn-conflictsmeant for Colab's pre-populated Python env; feel free to remove for stricter usage):
%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.
定义流水线参数：
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.'
...
摄入
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 | Milvus
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，这些来源包含丰富的定位信息，包括段落标题（即章节）、页码以及精确的边界框。