import logging
from typing import Dict, Iterator, List, Union
import requests
from langchain_core.documents import Document
from langchain_community.document_loaders.base import BaseBlobParser
from langchain_community.document_loaders.blob_loaders import Blob
logger = logging.getLogger(__name__)
[docs]
class ServerUnavailableException(Exception):
"""Exception raised when the Grobid server is unavailable."""
pass
[docs]
class GrobidParser(BaseBlobParser):
"""Load article `PDF` files using `Grobid`."""
[docs]
def __init__(
self,
segment_sentences: bool,
grobid_server: str = "http://localhost:8070/api/processFulltextDocument",
) -> None:
self.segment_sentences = segment_sentences
self.grobid_server = grobid_server
try:
requests.get(grobid_server)
except requests.exceptions.RequestException:
logger.error(
"GROBID server does not appear up and running, \
please ensure Grobid is installed and the server is running"
)
raise ServerUnavailableException
[docs]
def process_xml(
self, file_path: str, xml_data: str, segment_sentences: bool
) -> Iterator[Document]:
"""Process the XML file from Grobin."""
try:
from bs4 import BeautifulSoup
except ImportError:
raise ImportError(
"`bs4` package not found, please install it with " "`pip install bs4`"
)
soup = BeautifulSoup(xml_data, "xml")
sections = soup.find_all("div")
titles = soup.find_all("title")
if titles:
title = titles[0].text
else:
title = "No title found"
chunks = []
for section in sections:
sect = section.find("head")
if sect is not None:
for i, paragraph in enumerate(section.find_all("p")):
chunk_bboxes = []
paragraph_text = []
for i, sentence in enumerate(paragraph.find_all("s")):
paragraph_text.append(sentence.text)
sbboxes = []
if sentence.get("coords") is not None:
for bbox in sentence.get("coords").split(";"):
box = bbox.split(",")
sbboxes.append(
{
"page": box[0],
"x": box[1],
"y": box[2],
"h": box[3],
"w": box[4],
}
)
chunk_bboxes.append(sbboxes)
if (segment_sentences is True) and (len(sbboxes) > 0):
fpage, lpage = sbboxes[0]["page"], sbboxes[-1]["page"]
sentence_dict = {
"text": sentence.text,
"para": str(i),
"bboxes": [sbboxes],
"section_title": sect.text,
"section_number": sect.get("n"),
"pages": (fpage, lpage),
}
chunks.append(sentence_dict)
if segment_sentences is not True:
fpage, lpage = (
chunk_bboxes[0][0]["page"],
chunk_bboxes[-1][-1]["page"],
)
paragraph_dict = {
"text": "".join(paragraph_text),
"para": str(i),
"bboxes": chunk_bboxes,
"section_title": sect.text,
"section_number": sect.get("n"),
"pages": (fpage, lpage),
}
chunks.append(paragraph_dict)
yield from [
Document(
page_content=chunk["text"],
metadata=dict(
{
"text": str(chunk["text"]),
"para": str(chunk["para"]),
"bboxes": str(chunk["bboxes"]),
"pages": str(chunk["pages"]),
"section_title": str(chunk["section_title"]),
"section_number": str(chunk["section_number"]),
"paper_title": str(title),
"file_path": str(file_path),
}
),
)
for chunk in chunks
]
[docs]
def lazy_parse(self, blob: Blob) -> Iterator[Document]:
file_path = blob.source
if file_path is None:
raise ValueError("blob.source cannot be None.")
pdf = open(file_path, "rb")
files = {"input": (file_path, pdf, "application/pdf", {"Expires": "0"})}
try:
data: Dict[str, Union[str, List[str]]] = {}
for param in ["generateIDs", "consolidateHeader", "segmentSentences"]:
data[param] = "1"
data["teiCoordinates"] = ["head", "s"]
files = files or {}
r = requests.request(
"POST",
self.grobid_server,
headers=None,
params=None,
files=files,
data=data,
timeout=60,
)
xml_data = r.text
except requests.exceptions.ReadTimeout:
logger.error("GROBID server timed out. Return None.")
xml_data = None
if xml_data is None:
return iter([])
else:
return self.process_xml(file_path, xml_data, self.segment_sentences)
