Reading and Processing PDFs with pdfdol

Or add a decoder to an existing PdfFilesReader:

from dol import add_decoder

page_sep = '\n\n---\n\n'
pdfs = add_decoder(PdfFilesReader(folder), decoder=page_sep.join)

Extracting Text from PDF Bytes

When you have PDF content as bytes (from a download, database, API, etc.):

from pdfdol import pdf_bytes_to_text_pages, pdf_bytes_to_text

# Get a list of page strings
pages = list(pdf_bytes_to_text_pages(pdf_bytes))

# Get all text as one string
text = pdf_bytes_to_text(pdf_bytes)

PDF Metadata

from pdfdol.tools import pdf_to_title, pdf_to_metadata

# Extract title (returns None if not set)
title = pdf_to_title("document.pdf")
title = pdf_to_title(pdf_bytes)

# Extract full metadata dict
meta = pdf_to_metadata("document.pdf")
# {'Title': '...', 'Author': '...', 'Subject': '...', ...}

All metadata functions accept a file path (str), raw bytes, or a pypdf.PdfReader object.

Concatenating PDFs

concat_pdfs merges multiple PDFs (and images) into one.

From a folder

from pdfdol import concat_pdfs

# Merge all PDFs in a folder, return bytes
pdf_bytes = concat_pdfs("/path/to/folder", filter_extensions=True)

# Save to a file
concat_pdfs("/path/to/folder", save_filepath="combined.pdf",
            filter_extensions=True, key_order=sorted)

From a dict-like store

from dol import Files
from pdfdol import concat_pdfs

store = Files("/path/to/folder")
pdf_bytes = concat_pdfs(store, filter_extensions=True, key_order=sorted)

From a list of PDF bytes

from pdfdol.tools import concat_pdf_bytes

combined = concat_pdf_bytes([pdf1_bytes, pdf2_bytes, pdf3_bytes])

Ordering and filtering

# Sort alphabetically
concat_pdfs(store, key_order=sorted)

# Custom sort (e.g. by numeric prefix)
concat_pdfs(store, key_order=lambda k: int(k.split('_')[0]))

# Explicit order
concat_pdfs(store, key_order=['intro.pdf', 'chapter1.pdf', 'appendix.pdf'])

# Only include PDFs and images (skip .txt, .docx, etc.)
concat_pdfs(store, filter_extensions=True)

# Skip files that fail to convert (instead of raising)
concat_pdfs(store, skip_errors=True)

filter_extensions=True keeps: .pdf, .png, .jpg, .jpeg, .bmp, .gif, .tiff. Images are automatically converted to PDF pages before merging.

Save behavior

Utility Functions

from pdfdol.util import remove_empty_pages

# Remove pages with little/no text
remove_empty_pages("input.pdf", "cleaned.pdf")

Building Custom Pipelines

pdfdol uses dol.Pipe for composable transformations. You can build custom read pipelines:

from dol import Pipe
from pdfdol.base import bytes_to_pdf_reader_obj, pdf_reader_to_text_pages

# Custom pipeline: bytes -> reader -> text pages -> uppercased
my_reader = Pipe(
    bytes_to_pdf_reader_obj,
    pdf_reader_to_text_pages,
    lambda pages: [p.upper() for p in pages],
)

upper_pages = my_reader(pdf_bytes)

Quick Reference