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元数据提取

在许多情况下,尤其是处理长文档时,文本片段可能缺乏必要的上下文来将其与其他类似的文本片段区分开来。

为了解决这个问题,我们使用大型语言模型提取与文档相关的特定上下文信息,以更好地帮助检索和语言模型消除相似段落的歧义。

我们在一个示例笔记本中展示了这一点,并证明了其在处理长文档方面的有效性。

首先,我们定义一个元数据提取器,它接收一系列将按顺序处理的特征提取器。

然后我们将其输入节点解析器,该解析器将为每个节点添加额外的元数据。

from llama_index.core.node_parser import SentenceSplitter
from llama_index.core.extractors import (
SummaryExtractor,
QuestionsAnsweredExtractor,
TitleExtractor,
KeywordExtractor,
)
from llama_index.extractors.entity import EntityExtractor
transformations = [
SentenceSplitter(),
TitleExtractor(nodes=5),
QuestionsAnsweredExtractor(questions=3),
SummaryExtractor(summaries=["prev", "self"]),
KeywordExtractor(keywords=10),
EntityExtractor(prediction_threshold=0.5),
]

然后,我们可以在输入文档或节点上运行我们的转换:

from llama_index.core.ingestion import IngestionPipeline
pipeline = IngestionPipeline(transformations=transformations)
nodes = pipeline.run(documents=documents)

以下是一个提取的元数据示例:

{'page_label': '2',
'file_name': '10k-132.pdf',
'document_title': 'Uber Technologies, Inc. 2019 Annual Report: Revolutionizing Mobility and Logistics Across 69 Countries and 111 Million MAPCs with $65 Billion in Gross Bookings',
'questions_this_excerpt_can_answer': '\n\n1. How many countries does Uber Technologies, Inc. operate in?\n2. What is the total number of MAPCs served by Uber Technologies, Inc.?\n3. How much gross bookings did Uber Technologies, Inc. generate in 2019?',
'prev_section_summary': "\n\nThe 2019 Annual Report provides an overview of the key topics and entities that have been important to the organization over the past year. These include financial performance, operational highlights, customer satisfaction, employee engagement, and sustainability initiatives. It also provides an overview of the organization's strategic objectives and goals for the upcoming year.",
'section_summary': '\nThis section discusses a global tech platform that serves multiple multi-trillion dollar markets with products leveraging core technology and infrastructure. It enables consumers and drivers to tap a button and get a ride or work. The platform has revolutionized personal mobility with ridesharing and is now leveraging its platform to redefine the massive meal delivery and logistics industries. The foundation of the platform is its massive network, leading technology, operational excellence, and product expertise.',
'excerpt_keywords': '\nRidesharing, Mobility, Meal Delivery, Logistics, Network, Technology, Operational Excellence, Product Expertise, Point A, Point B'}

如果提供的提取器不符合您的需求,您也可以像这样定义自定义提取器:

from llama_index.core.extractors import BaseExtractor
class CustomExtractor(BaseExtractor):
async def aextract(self, nodes) -> List[Dict]:
metadata_list = [
{
"custom": node.metadata["document_title"]
+ "\n"
+ node.metadata["excerpt_keywords"]
}
for node in nodes
]
return metadata_list

extractor.extract() 将在底层自动调用 aextract(),以提供同步和异步两种入口点。

在一个更高级的示例中,它还可以利用 llm 从节点内容和现有元数据中提取特征。有关更多详细信息,请参阅提供的元数据提取器的源代码

以下您将找到各种元数据提取器的指南和教程。