difficulties in install of weasyprint for Python 3.4 virtualenv, Win7

[dborisog]

I followed the instructions from http://weasyprint.readthedocs.io/en/latest/install.html#windows

test & error message

>python -m weasyprint http://weasyprint.org weasyprint.pdf
Traceback (most recent call last):
  File "c:\python34\Lib\runpy.py", line 151, in _run_module_as_main
    mod_name, mod_spec, code = _get_module_details(mod_name)
  File "c:\python34\Lib\runpy.py", line 118, in _get_module_details
    return _get_module_details(pkg_main_name)
  File "c:\python34\Lib\runpy.py", line 104, in _get_module_details
    spec = importlib.util.find_spec(mod_name)
  File "C:\Users\user\Envs\ch_dev\lib\importlib\util.py", line 86, in find_spec
    parent = __import__(parent_name, fromlist=['__path__'])
  File "C:\Users\user\Envs\ch_dev\lib\site-packages\weasyprint\__init__.py", line 338, in <module>
    from .css import PARSER, preprocess_stylesheet  # noqa
  File "C:\Users\user\Envs\ch_dev\lib\site-packages\weasyprint\css\__init__.py", line 30, in <module>
    from . import computed_values
  File "C:\Users\user\Envs\ch_dev\lib\site-packages\weasyprint\css\computed_values.py", line 18, in <module>
    from .. import text
  File "C:\Users\user\Envs\ch_dev\lib\site-packages\weasyprint\text.py", line 216, in <module>
    'libgobject-2.0.dylib')
  File "C:\Users\user\Envs\ch_dev\lib\site-packages\weasyprint\text.py", line 212, in dlopen
    return ffi.dlopen(names[0])  # pragma: no cover
  File "C:\Users\user\Envs\ch_dev\lib\site-packages\cffi\api.py", line 139, in dlopen
    lib, function_cache = _make_ffi_library(self, name, flags)
  File "C:\Users\user\Envs\ch_dev\lib\site-packages\cffi\api.py", line 769, in _make_ffi_library
    backendlib = _load_backend_lib(backend, libname, flags)
  File "C:\Users\user\Envs\ch_dev\lib\site-packages\cffi\api.py", line 758, in _load_backend_lib
    return backend.load_library(name, flags)
OSError: cannot load library gobject-2.0: error 0x7e

pip freeze

>pip freeze
cairocffi==0.7.2
CairoSVG==1.0.22
cffi==1.8.3
cssselect==1.0.0
Django==1.10.2
django-appconf==1.0.2
django-ckeditor==5.1.1
django-compressor==2.1
django-debug-toolbar==1.6
django-grappelli==2.8.2
django-taggit==0.21.3
django-taggit-autosuggest==0.3.0
html5lib==0.999999999
lxml==3.6.4
mysqlclient==1.3.8
Pillow==3.4.2
pycparser==2.16
Pyphen==0.9.4
rcssmin==1.0.6
rjsmin==1.0.12
six==1.10.0
sqlparse==0.2.1
tinycss==0.3
WeasyPrint==0.31
webencodings==0.5

search in Python libraries

Searching 6610 files for "gobject-2.0" (regex)

C:\Users\user\Envs\ch_dev\Lib\site-packages\cairocffi\pixbuf.py:
30
31 gdk_pixbuf = dlopen(ffi, 'gdk_pixbuf-2.0', 'gdk_pixbuf-2.0-0')
32: gobject = dlopen(ffi, 'gobject-2.0', 'gobject-2.0-0')
33 glib = dlopen(ffi, 'glib-2.0', 'glib-2.0-0')
34 try:

C:\Users\user\Envs\ch_dev\Lib\site-packages\weasyprint\text.py:
213
214
215: gobject = dlopen(ffi, 'gobject-2.0', 'libgobject-2.0-0', 'libgobject-2.0.so',
216: 'libgobject-2.0.dylib')
217 pango = dlopen(ffi, 'pango-1.0', 'libpango-1.0-0', 'libpango-1.0.so',
218 'libpango-1.0.dylib')

6 matches across 2 files

part of PATH

> print(os.environ.get('PATH')) # contains
...; C:\Program Files (x86)\Graphviz2.38\bin;C:\Program Files (x86)\Graphviz2.38\lib; ... ;C:\Program Files\GTK3-Runtime Win64\lib;

DLL present

I have C:\Program Files\GTK3-Runtime Win64\lib\libgobject-2.0-0.dll

quickfix

after playing with dlopen() functions I got a message informing of a problem with DLL in Graphviz, so I changed the order of PATH instructions placing GTK before Graphviz. After that the test almost worket producing the following error

>python -m weasyprint http://weasyprint.org weasyprint.pdf
Failed to load stylesheet at https://fonts.googleapis.com/css?family=Oswald : URLError: <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:600)>
Failed to load stylesheet at https://fonts.googleapis.com/css?family=Alegreya+Sans:400,400italic,700 : URLError: <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:600)>
Failed to load stylesheet at https://fonts.googleapis.com/css?family=Cousine : URLError: <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:600)>
Ignored `transition: color 0.25s` at 14:18, unknown property.
Ignored `text-shadow: 1px 1px 1px #111` at 18:125, unknown property.

(python.exe:7236): Pango-WARNING **: couldn't load font "Cousine Not-Rotated 12.9599609375px", falling back to "Sans Not-Rotated 12.9599609375px", expect ugly output.

[liZe]

Thank you for reporting this issue.

after playing with dlopen() functions I got a message informing of a problem with DLL in Graphviz, so I changed the order of PATH instructions placing GTK before Graphviz.

There's probably a 32-bit gobject installed with Graphviz (it's installed in Program Files (x86)), WeasyPrint tries to import it but it fails. There's nothing we can (should?) do in WeasyPrint about that, that's a common problem when multiple versions of a lib are installed on a system. A possible solution is to set different PATHs for different softwares.

After that the test almost worket producing the following error

That's not errors, just warnings. You probably just have generated your first PDF 😉.

[dborisog]

Thank you for the quick response, after your comment I understand the issue now.