installing PyQt

[Michael Mossey]

Hi, I'm trying to install PyQt for windows together with
non-commercial Qt version 2.3.0. When I try to run a sample Qt
program I get this error:

File "c:/DOCUME~1/mossey/LOCALS~1/Temp/python-1872fAk", line 1, in ?
from main_qt import *
File "main_qt.py", line 2, in ?
from qt import *
File "C:\PROGRA~1\Python22\lib\site-packages\qt.py", line 17, in ?
import libsip
ImportError: DLL load failed: The specified module could not be found.

I'm assuming it can't find libsip.dll. This file is located in the
directory C:\Program Files\Python22\Lib\site-packages\ and I added
that directory to both the PYTHONPATH and the PATH. This is windows
2000 so I used the system dialog to do it, and then rebooted the
computer (I don't know if rebooting is necessary). I keep getting the
same error. I tried copying libsip.dll to the C:\winnt directory and
it still didn't find it. Can someone familiar with Python on Windows
2000 give me a clue here?

Regards,
Mike

 

[Michael Mossey]

It's hard to believe that it won't find libsip.dll if it's in the
site-packages directory since that's part of your default Python
search path (even without a PYTHONPATH setting). And since libsip is
a direct "import" (and not a system DLL dependency), the search path
that governs things is Pythons (e.g., sys.path, including PYTHONPATH)
and not the Windows system search path (aka PATH).

But it wouldn't hurt for you to verify sys.path after starting a copy
of Python just to ensure that it has all the directories you expect.

So if we assume libsip itself is found, the problem could be in
loading it due to another dependency. Do you have the underlying Qt
DLL (I forget the exact name for the non-commercial version) also
somewhere in the system PATH? libsip.dll depends on the Qt DLL, and
if it fails to find it, libsip in turn will fail to load and can
produce precisely the traceback as above.

Although if it is a failing dependent DLL, in such a case typically
you'll also get a system dialog complaining about not finding the
underlying dependent DLL, but maybe you've just answered that dialog
without reading it closely? (or maybe somehow those dialogs are being
suppressed in your setup)

Another alternative would be some other dependency - it might be worth
checking if all the dependencies for libsip.dll can be resolved on
your system. A tool like depends (comes with various MS
toolkits/development environments), or cygcheck (if you have cygwin)
or others you can download can check this.

-- David

Hi, thanks very much. Your information was helpful in tracking down
the problem, which turned out to be that PyQt was built against Python
2.3 and I was running Python 2.2.2. I'm running Python from Emacs, so
I had to do a few more things to get Emacs to recognize a new version
of python -- turns out I had to re-byte-compile the python-mode.el
file. It all seems to work now. Although you didn't suggest this
solution directly, your information allowed me to eliminate things and
quickly move toward the right answer. Isn't it neat how that works?

-Mike