app.py

import gradio as gr
from haystack.document_stores import InMemoryDocumentStore
from haystack.nodes import FARMReader, PreProcessor, PDFToTextConverter, TfidfRetriever
import logging

document_store = InMemoryDocumentStore()
preprocessor = PreProcessor(
    clean_empty_lines=True,
    clean_whitespace=True,
    clean_header_footer=True,
    split_by="word",
    split_length=100,
    split_respect_sentence_boundary=True,
    split_overlap=3
)


def pdf_to_document_store(pdf_files):
    document_store.delete_documents()
    converter = PDFToTextConverter(remove_numeric_tables=True, valid_languages=["en"])
    documents = []
    for pdf in pdf_files:
        documents.append(converter.convert(file_path=pdf.name, meta=None))
    preprocessed_docs = preprocessor.process(documents)
    document_store.write_documents(preprocessed_docs)
    return None


def summarize(files):
    if files is not None:
        document_store.delete_all_documents()
        pdf_to_document_store(files)
    return document_store.get_document_count()

title = "Summarize one or more PDFs with a Haystack Summariser pipeline"
iface = gr.Interface(fn=summarize,
                    inputs=[gr.inputs.File(file_count="multiple", type="file", label="Upload some PDFs")],
                    outputs="text",
                    title=title,
                    theme="huggingface")
iface.launch()