pdfparser

Python binding for libpoppler - focused on text extraction from PDF documents.

Intended as an easy to use replacement for pdfminer, which provides much better performance (see below for short comparison) and is Python 3 compatible. This packages is based on izderadicka/pdfparser and almost completely rewritten, so the package name changed to pdfparser-rossum to avoid conflicting builds.

See this article for some comparisons with pdfminer and other approaches.

The binding is written in cython. It works with Python 3 (but is not perfectly polished) and on Ubuntu 18.04 and 20.04. It depends on poppler, cairo and pycairo. For Ubuntu it is needed to use packages of poppler from a PPA custom some fixes until they get to upstream.

It is available under GPL v3 or any later version license (since libpoppler is also GPL).

Installing

Requirements

It depends on poppler >= 0.86.1 (DEB: libpoppler-dev, libpoppler-private-dev) and cairo (libcairo2-dev). Also it's recommended to use libcairo2-dev>=1.14.8 which solves some deadlock bug.

The poppler needs to export some CairoOutputDev symbols (currently with a patch and a custom build).

Compatible builds:

• Ubuntu 18.04 (apt)
  • poppler-0.86.1-0ubuntu1ppa~bionic1
• Ubuntu 20.04 (apt)
  • poppler-0.86.1-0ubuntu1ppa~focal3
• Mac (homebrew)
  • rossumai/formulas/[email protected]
  • rossumai/formulas/[email protected]

See the .Dockerfile.gitlab-ci for installation.

Some workarounds for virtualenv and MacOS - export those before installing pycairo and pdfparser-rossum.

# pycairo (for pdfparser) in virtualenv, make its pkg-config visible
# https://gitlab.rossum.cloud/rossum/pdfparser/issues/13#solution
if [[ ! -z "$VIRTUAL_ENV" ]]; then
    export PKG_CONFIG_PATH="${VIRTUAL_ENV}/lib/pkgconfig:${PKG_CONFIG_PATH}"
fi

if [[ $(uname -s) == Darwin* ]]; then
    # some workarounds on Mac

    # libffi (for pdfparser), make its pkg-config visible
    export PKG_CONFIG_PATH="/usr/local/opt/libffi/lib/pkgconfig:${PKG_CONFIG_PATH}"
fi

Besides that there are dependencies on Python packages: cython at build time and pycairo>=1.16.0 (installed from source, as wheel does not provide pycairo.h and pycairo.pc files).

# while building a source package
pip install cython
# at build and run time
pip install pycairo>=1.16.0 --no-binary pycairo

Note that pycairo currently needs to be installed in a separate command before pdfparser-rossum as it's necessary at the build time and pip in not able to resolve the dependency graph.

See the .Dockerfile.gitlab-ci how to install the requirements. Such image might be useful for building the source package for distribution or for trying out pdfparser.

How to install via pip

Given a pre-built source package, it's easy to install.

It's on PyPI: https://pypi.org/project/pdfparser-rossum/

# from a PyPI repo
pip install pdfparser-rossum

Possibly you can build an install from source:

# from a source package
pip install pdfarser-rossum-*.tar.gz

Windows fonts

Optionally you may want to install some old Windows fonts.

sudo ./install_fonts.sh

Building without docker

If you have installed the build requirements on the host machine, you can just build the source package.

# produces eg. dist/pdfparser-rossum-<VERSION>.tar.gz
$ python setup.py sdist

It can be done fine even on macOS (see below).

Building with Docker

docker build -t pdfparser .

# it's possible to mount to container to obtain the build artifact
# or you can publish it to a PyPI repo from there using twine
$ docker run --rm -it -v $(pwd)/dist:/build/pdfparser/dist pdfparser bash

# inside the container:
$ python setup.py sdist

The build artifact is inside the image in /pdfparser/dist/.

Releasing

Make sure the proper version is set at setup.py. Ideally build the final releases from master branch. For example last released branch is 1.2.0.

• in develop set the version to be released in setup.py, eg. 1.2.1.dev to 1.2.1
• merge to master
• build with the new version
• tag v1.2.1
• publish the artifacts to a custom PyPI repo using twine
• checkout develop
• increment to next dev version, eg. 1.2.2.dev

Publishing

We'd like to publish the source package (*.tar.gz) to some PyPI repository, either the public one or to some private one.

This assumes you have configured ~/.pypirc with you repo.

Example ~/.pypirc for custom repo:

[distutils]
index-servers =
    pypi
    myrepo

[pypi]

[myrepo]
repository=https://pypi.example.com/
username=some_user
password=some_secret_password

Publish:

pip install twine
twine upload -r myrepo dist/pdfparser-rossum-*.tar.gz

Development

It's possible to develop locally or within Docker. The latter isolates the environment but source code should be mounted from editing at the host.

# Example

docker build -f .Dockerfile.gitlab-ci -t pdfparser:dev .
# Run docker container with local source code mounted in
docker run --rm -it -v $(pwd):/pdfparser pdfparser:dev bash

pip3 install -v -e .
# do whatever tests you need...
tests/dump_file.py foo.pdf
# rinse and repeat...

Installing on macOS

Tap with custom brew formulas for poppler rossumai/homebrew-formulas - custom build with CairoOutputDev symbols exported.

brew tap rossumai/formulas
brew install [email protected]
brew link [email protected]

Installing dependencies.

brew install pkg-config cairo libffi

Installing an already build package. Note that pycairo has to be installed from source, not as a binary wheel, so that it provides the headers and pkg-config file.

With libffi from homebrew PKG_CONFIG_PATH needs to be provided, it's needed for installing both pycairo and pdfparser-rossum. See: otrv4/pidgin-otrng#104 (comment)

export PKG_CONFIG_PATH=/usr/local/opt/libffi/lib/pkgconfig
pip install pycairo>=1.16.0 --no-binary pycairo
pip install pdfparser-rossum

Building and installing:

git clone https://github.com/rossumai/pdfparser.git
cd pdfparser/

export PKG_CONFIG_PATH=/usr/local/opt/libffi/lib/pkgconfig
pip install -r requirements.txt

# for general usage
pip install .

# for development
pip install -e .

# to get the compilation details
pip install -v -e .

Usage

See tests/dump_file.py for an example of usage.

Note: It needs correct locale (especially on Ubuntu Bionic and maybe earlier).

export LC_ALL=C.UTF-8
python tests/dump_file.py test_docs/test1.pdf

Regression test

See tests/extract_data.py and tests/compare_images.py.

Speed comparisons

	pdfreader	pdfminer	speed-up factor
tiny document (half page)	0.033s	0.121s	3.6 x
small document (5 pages)	0.141s	0.810s	5.7 x
medium document (55 pages)	1.166s	10.524s	9.0 x
large document (436 pages)	10.581s	108.095s	10.2 x

pdfparser code used in test

import pdfparser.poppler as pdf
import sys

d = pdf.PopplerDocument(sys.argv[1].encode('utf-8'))

print('No of pages', d.page_count)
for p in d:
    print('Page', p.page_no, 'size =', p.size)
    for f in p:
        print(' '*1,'Flow')
        for b in f:
            print(' '*2,'Block', 'bbox=', b.bbox.as_tuple())
            for l in b:
                print(' '*3, l.text, '(%0.2f, %0.2f, %0.2f, %0.2f)'% l.bbox.as_tuple())
                #assert l.char_fonts.comp_ratio < 1.0
                for i in range(len(l.text)):
                    print(l.text[i], '(%0.2f, %0.2f, %0.2f, %0.2f)'% l.char_bboxes[i].as_tuple(),\
                        l.char_fonts[i].name, l.char_fonts[i].size, l.char_fonts[i].color,)
                print()

Version info

Version of Poppler:

from pdfparser.poppler import POPPLER_VERSION
print(POPPLER_VERSION)
# 20.09.0

Version of Pdfparser:

import pkg_resources
print(pkg_resources.get_distribution('pdfparser-rossum').version)

Error verbosity

By default Poppler may throw a lot of syntax warning and errors. In some cases we may want to suppress it. For that there's a global property pdfparser.params.error_quiet: bool.

import pdfparser

pdfparser.PopplerDocument('test_docs/test1.odt'.encode('utf-8'))

# Syntax Warning: May not be a PDF file (continuing anyway)
# Syntax Error: Couldn't find trailer dictionary
# Syntax Error: Couldn't find trailer dictionary
# Syntax Error: Couldn't read xref table
# ...

pdfparser.params.error_quiet = True

pdfparser.PopplerDocument('test_docs/test1.odt'.encode('utf-8'))
# quiet...