from typing import Any, Iterator, Optional
from langchain_core.documents import Document
from langchain_community.document_loaders.base import BaseBlobParser
from langchain_community.document_loaders.blob_loaders import Blob
[docs]class AzureAIDocumentIntelligenceParser(BaseBlobParser):
"""Loads a PDF with Azure Document Intelligence
(formerly Forms Recognizer)."""
[docs] def __init__(
self,
api_endpoint: str,
api_key: str,
api_version: Optional[str] = None,
api_model: str = "prebuilt-layout",
mode: str = "markdown",
):
from azure.ai.documentintelligence import DocumentIntelligenceClient
from azure.core.credentials import AzureKeyCredential
kwargs = {}
if api_version is not None:
kwargs["api_version"] = api_version
self.client = DocumentIntelligenceClient(
endpoint=api_endpoint,
credential=AzureKeyCredential(api_key),
headers={"x-ms-useragent": "langchain-parser/1.0.0"},
**kwargs,
)
self.api_model = api_model
self.mode = mode
assert self.mode in ["single", "page", "object", "markdown"]
def _generate_docs_page(self, result: Any) -> Iterator[Document]:
for p in result.pages:
content = " ".join([line.content for line in p.lines])
d = Document(
page_content=content,
metadata={
"page": p.page_number,
},
)
yield d
def _generate_docs_single(self, result: Any) -> Iterator[Document]:
yield Document(page_content=result.content, metadata={})
def _generate_docs_object(self, result: Any) -> Iterator[Document]:
# record relationship between page id and span offset
page_offset = []
for page in result.pages:
# assume that spans only contain 1 element, to double check
page_offset.append(page.spans[0]["offset"])
# paragraph
# warning: paragraph content is overlapping with table content
for para in result.paragraphs:
yield Document(
page_content=para.content,
metadata={
"role": para.role,
"page": para.bounding_regions[0].page_number,
"bounding_box": para.bounding_regions[0].polygon,
"type": "paragraph",
},
)
# table
for table in result.tables:
yield Document(
page_content=table.cells, # json object
metadata={
"footnote": table.footnotes,
"caption": table.caption,
"page": para.bounding_regions[0].page_number,
"bounding_box": para.bounding_regions[0].polygon,
"row_count": table.row_count,
"column_count": table.column_count,
"type": "table",
},
)
[docs] def lazy_parse(self, blob: Blob) -> Iterator[Document]:
"""Lazily parse the blob."""
with blob.as_bytes_io() as file_obj:
poller = self.client.begin_analyze_document(
self.api_model,
file_obj,
content_type="application/octet-stream",
output_content_format="markdown" if self.mode == "markdown" else "text",
)
result = poller.result()
if self.mode in ["single", "markdown"]:
yield from self._generate_docs_single(result)
elif self.mode in ["page"]:
yield from self._generate_docs_page(result)
else:
yield from self._generate_docs_object(result)
[docs] def parse_url(self, url: str) -> Iterator[Document]:
from azure.ai.documentintelligence.models import AnalyzeDocumentRequest
poller = self.client.begin_analyze_document(
self.api_model,
AnalyzeDocumentRequest(url_source=url),
# content_type="application/octet-stream",
output_content_format="markdown" if self.mode == "markdown" else "text",
)
result = poller.result()
if self.mode in ["single", "markdown"]:
yield from self._generate_docs_single(result)
elif self.mode in ["page"]:
yield from self._generate_docs_page(result)
else:
yield from self._generate_docs_object(result)