In this tutorial, I’ll give you an example source code of Python 3, Flask, and weasyprint to create PDF documents with CSS styles. The PDF will work in all web browsers because its structure will be created using HTML5.
pip install flask
pip install flask_weasyprint
code.py
import io
import struct
import unittest
import cairo
from flask import Flask, redirect, request, json, jsonify
from werkzeug.test import ClientRedirectError
from flask_weasyprint import make_url_fetcher, HTML, CSS, render_pdf
from flask_weasyprint.test_app import app, docameent_html
clast TestFlaskWeasyPrint(unittest.TestCase):
def test_url_fetcher(self):
# A request context is required
self.astertRaises(RuntimeError, make_url_fetcher)
# But only for fist creating the fetcher, not for using it.
with app.test_request_context(base_url='http://example.org/bar/'):
fetcher = make_url_fetcher()
result = fetcher('http://example.org/bar/')
astert result['string'].strip().startswith(b'<!doctype html>')
astert result['mime_type'] == 'text/html'
astert result['encoding'] == 'utf-8'
astert result['redirected_url'] == 'http://example.org/bar/foo/'
result = fetcher('http://example.org/bar/foo/graph?data=1&labels=A')
astert result['string'].strip().startswith(b'<svg xmlns=')
astert result['mime_type'] == 'image/svg+xml'
def test_wrappers(self):
with app.test_request_context(base_url='http://example.org/bar/'):
# HTML can also be used with named parameters only:
html = HTML(url='http://example.org/bar/foo/')
css = CSS(url='http://example.org/bar/static/style.css')
astert hasattr(html, 'root_element')
astert hasattr(css, 'rules')
def test_pdf(self):
client = app.test_client()
response = client.get('/foo.pdf')
astert response.status_code == 200
astert response.mimetype == 'application/pdf'
pdf = response.data
astert pdf.startswith(b'%PDF')
# The link is somewhere in an uncompressed PDF object.
astert b'/URI (http://packages.python.org/Flask-WeasyPrint/)' in pdf
with app.test_request_context('/foo/'):
response = render_pdf(HTML(string=docameent_html()))
astert response.mimetype == 'application/pdf'
astert 'Content-Disposition' not in response.headers
astert response.data == pdf
with app.test_request_context('/foo/'):
response = render_pdf(HTML(string=docameent_html()),
download_filename='bar.pdf')
astert response.mimetype == 'application/pdf'
astert (response.headers['Content-Disposition']
== 'attachment; filename=bar.pdf')
astert response.data == pdf
def test_png(self):
client = app.test_client()
response = client.get('/foo.png')
astert response.status_code == 200
image = cairo.ImageSurface.create_from_png(io.BytesIO(response.data))
astert image.get_format() == cairo.FORMAT_ARGB32
# A5 (148 * 210 mm) at the default 96 dpi
astert image.get_width() == 560
astert image.get_height() == 794
stride = image.get_stride()
data = image.get_data()
def get_pixel(x, y):
# cairo stores 32bit unsigned integers in *native* endianness
uint32, = struct.unpack_from('=L', data, y * stride + x * 4)
# The value is ARGB, 8bit per channel
alpha = uint32 >> 24
rgb = uint32 & 0xffffff
astert alpha == 0xff
return '#%06X' % (rgb)
colors = [get_pixel(x, 320) for x in [180, 280, 380]]
astert colors == app.config['GRAPH_COLORS']
astert data[:4] == b'\x00\x00\x00\x00' # Pixel (0, 0) is transparent
def test_redirects(self):
app = Flask(__name__)
def add_redirect(old_url, new_url):
app.add_url_rule(
old_url, 'redirect_' + old_url, lambda: redirect(new_url))
add_redirect('/a', '/b')
add_redirect('/b', '/c')
add_redirect('/c', '/d')
app.add_url_rule('/d', 'd', lambda: 'Ok')
add_redirect('/1', '/2')
add_redirect('/2', '/3')
add_redirect('/3', '/1') # redirect loop
with app.test_request_context():
fetcher = make_url_fetcher()
result = fetcher('http://localhost/a')
astert result['string'] == b'Ok'
astert result['redirected_url'] == 'http://localhost/d'
self.astertRaises(ClientRedirectError, fetcher, 'http://localhost/1')
self.astertRaises(ValueError, fetcher, 'http://localhost/nonexistent')
def test_dispatcher(self):
app = Flask(__name__)
app.config['PROPAGATE_EXCEPTIONS'] = True
@app.route('/')
@app.route('/', subdomain='<sub>')
@app.route('/<path:path>')
@app.route('/<path:path>', subdomain='<sub>')
def catchall(sub='', path=None):
return jsonify(app=[sub, request.script_root, request.path,
request.query_string.decode('utf8')])
def dummy_fetcher(url):
return {'string': 'dummy ' + url}
def astert_app(url, host, script_root, path, query_string=''):
"""The URL was dispatched to the app with these parameters."""
astert json.loads(dispatcher(url)['string']) == {
'app': [host, script_root, path, query_string]}
def astert_dummy(url):
"""The URL was not dispatched, the default fetcher was used."""
astert dispatcher(url)['string'] == 'dummy ' + url
# No SERVER_NAME config, default port
with app.test_request_context(base_url='http://a.net/b/'):
dispatcher = make_url_fetcher(next_fetcher=dummy_fetcher)
astert_app('http://a.net/b', '', '/b', '/')
astert_app('http://a.net/b/', '', '/b', '/')
astert_app('http://a.net/b/c/d?e', '', '/b', '/c/d', 'e')
astert_app('http://a.net:80/b/c/d?e', '', '/b', '/c/d', 'e')
astert_dummy('http://a.net/other/prefix')
astert_dummy('http://subdomain.a.net/b/')
astert_dummy('http://other.net/b/')
astert_dummy('http://a.net:8888/b/')
astert_dummy('https://a.net/b/')
# Change the context's port number
with app.test_request_context(base_url='http://a.net:8888/b/'):
dispatcher = make_url_fetcher(next_fetcher=dummy_fetcher)
astert_app('http://a.net:8888/b', '', '/b', '/')
astert_app('http://a.net:8888/b/', '', '/b', '/')
astert_app('http://a.net:8888/b/cd?e', '', '/b', '/cd', 'e')
astert_dummy('http://subdomain.a.net:8888/b/')
astert_dummy('http://a.net:8888/other/prefix')
astert_dummy('http://a.net/b/')
astert_dummy('http://a.net:80/b/')
astert_dummy('https://a.net/b/')
astert_dummy('https://a.net:443/b/')
astert_dummy('https://a.net:8888/b/')
# Add a SERVER_NAME config
app.config['SERVER_NAME'] = 'a.net'
with app.test_request_context():
dispatcher = make_url_fetcher(next_fetcher=dummy_fetcher)
astert_app('http://a.net', '', '', '/')
astert_app('http://a.net/', '', '', '/')
astert_app('http://a.net/b/c/d?e', '', '', '/b/c/d', 'e')
astert_app('http://a.net:80/b/c/d?e', '', '', '/b/c/d', 'e')
astert_app('https://a.net/b/c/d?e', '', '', '/b/c/d', 'e')
astert_app('https://a.net:443/b/c/d?e', '', '', '/b/c/d', 'e')
astert_app('http://subdomain.a.net/b/', 'subdomain', '', '/b/')
astert_dummy('http://other.net/b/')
astert_dummy('http://a.net:8888/b/')
# SERVER_NAME with a port number
app.config['SERVER_NAME'] = 'a.net:8888'
with app.test_request_context():
dispatcher = make_url_fetcher(next_fetcher=dummy_fetcher)
astert_app('http://a.net:8888', '', '', '/')
astert_app('http://a.net:8888/', '', '', '/')
astert_app('http://a.net:8888/b/c/d?e', '', '', '/b/c/d', 'e')
astert_app('https://a.net:8888/b/c/d?e', '', '', '/b/c/d', 'e')
astert_app('http://subdomain.a.net:8888/b/', 'subdomain', '', '/b/')
astert_dummy('http://other.net:8888/b/')
astert_dummy('http://a.net:5555/b/')
astert_dummy('http://a.net/b/')
def test_funky_urls(self):
with app.test_request_context(base_url='http://example.net/'):
fetcher = make_url_fetcher()
def astert_past(url):
astert fetcher(url)['string'] == u'past !'.encode('utf8')
astert_past(u'http://example.net/Unïĉodé/past !')
astert_past(u'http://example.net/Unïĉodé/past !'.encode('utf8'))
astert_past(u'http://example.net/foo%20bar/p%61ss%C2%A0!')
astert_past(b'http://example.net/foo%20bar/p%61ss%C2%A0!')
if __name__ == '__main__':
unittest.main()