repository·main·Indexed 27 days ago
https://github.com/kozea/weasyprintA Python-based visual rendering engine that converts HTML and CSS into high-quality PDF documents. It provides a command-line API and a Python library featuring classes like HTML, CSS, and Attachment for document generation. WeasyPrint supports advanced printing standards including PDF/A, PDF/UA, and PDF/X, as well as specialized formats like Factur-X/ZUGFeRD electronic invoices. Key features include support for CSS page selectors, named strings for headers/footers, automatic hyphenation, and PDF interactive elements like hyperlinks and forms.
WeasyPrint follows a multi-step process to transform HTML and CSS into a PDF document, similar to how web browsers work:
z-index) and drawn onto PDF pages.You can quickly render a URL to a PDF or apply inline stylesheets using the HTML and CSS classes.
Security Warning: Using WeasyPrint with untrusted HTML or untrusted CSS may lead to security problems.
from weasyprint import HTML
HTML('https://weasyprint.org/').write_pdf('/tmp/weasyprint-website.pdf')When processing HTML, CSS, or SVG from untrusted sources, WeasyPrint is susceptible to security risks including high memory consumption, infinite rendering loops, and local file leaks.
To mitigate these risks, follow these best practices:
Specially crafted documents can cause high CPU/memory usage or infinite loops. To prevent this:
evil-reload-on-as and harakiri in uWSGI, or ulimit on Linux).WeasyPrint can reach network resources via https:// or ftp:// URIs. While there is a default 10-second timeout for these protocols, they can still cause issues.
file:// URIs.WeasyPrint can access local files using file:// URIs (e.g., in <img> or <embed> tags), which can be exploited to leak sensitive files or cause infinite rendering (e.g., via /dev/urandom).
file:// URLs or filters access based on allowed paths.WeasyPrint and its dependencies (Pango, etc.) may leak information about installed fonts, network configuration, or library versions. Use the isolation methods above to minimize the impact of such leaks.
Documentation is managed with Sphinx and is located in the docs folder. To build the documentation locally, run:
venv/bin/sphinx-build docs docs/_buildOnce built, you can view the documentation by opening docs/_build/index.html in your web browser.
To control image size and quality in the generated PDF, use the following parameters:
optimize_images: Enables size optimization (may increase rendering time).jpeg_quality: Sets JPEG quality from 0 (smallest size) to 95 (best quality).dpi: Sets the resolution in dots per inch to reduce raster image size.cache: Allows sharing an image cache between documents to save network and CPU time. You can pass a dictionary for in-memory caching or a string representing a folder path for disk-based caching (via --cache-folder CLI).# Optimized lower-quality images, slightly slower but smaller PDF
HTML('https://weasyprint.org/').write_pdf(
'weasyprint.pdf', optimize_images=True, jpeg_quality=60, dpi=150
)
# Using a shared cache between multiple documents
cache = {}
for i in range(10):
HTML(f'https://weasyprint.org/').write_pdf(
f'example-{i}.pdf', cache=cache
)You can attach files to a PDF using three different methods:
<a rel="attachment" href="filename.ext"> for links that open the file.<link rel="attachment" href="filename.ext"> in the <head> to attach a file globally to the document.--attachment CLI flag (can be used multiple times) or the weasyprint.Attachment class in Python.<!-- Method 1: Anchor -->
<a rel="attachment" href="note.txt">view attached note</a>
<!-- Method 2: Global Link -->
<link rel="attachment" href="note.txt">$ weasyprint document.html --attachment note.txt --attachment photo.jpg document.pdffrom weasyprint import Attachment, HTML
attachments = [Attachment("note.txt"), Attachment("photo.jpg")]
HTML(string="<p>PDF with attachments</p>").write_pdf("recipe.pdf", attachments=attachments)To install WeasyPrint using the system package manager:
apk add weasyprintTo install inside a virtualenv using wheels, you need these dependencies:
apk add py3-pip so:libgobject-2.0.so.0 so:libpango-1.0.so.0 so:libharfbuzz.so.0 so:libharfbuzz-subset.so.0 so:libfontconfig.so.1 so:libpangoft2-1.0.so.0To install inside a virtualenv without using wheels (building from source), you need these dependencies:
apk add py3-pip so:libgobject-2.0.so.0 so:libpango-1.0.so.0 so:libharfbuzz.so.0 so:libharfbuzz-subset.so.0 so:libfontconfig.so.1 so:libpangoft2-1.0.so.0
apk add gcc musl-dev python3-dev zlib-dev jpeg-dev openjpeg-dev libwebp-dev g++ libffi-devapk add weasyprintTests are located in the tests folder and use pytest.
Prerequisites:
Run the tests using:
venv/bin/python -m pytestWeasyPrint can generate specialized PDF variants using the --pdf-variant CLI option or the pdf_variant parameter in the HTML.write_pdf method. Supported variants can be listed via weasyprint --help.
Important Note: To ensure a valid document, your HTML and CSS must comply with the specific limitations of the chosen standard. Even if WeasyPrint attempts to generate a valid document, compliance is not guaranteed if the source content violates the specification.
from weasyprint import HTML
HTML(string="<p>document</p>").write_pdf("document.pdf", pdf_variant="pdf/a-3u")