PyImport_ImportModule("PyQt4.QtGui") fails

Question

I've got a C++ windows app that is trying to load a PyQt4 object, similar to the way PyQt4 does it for providing python widgets in the QtDesigner. The app loads other Python modules just fine, but fails to load PyQt4.QtGui. Also, with straight Python, I can load PyQt4.QtGui just fine. The debug output when it attempts that is:

'devenv.exe': Loaded 'C:\Python26\Lib\site-packages\PyQt4\QtGui.pyd', Binary was not built with debug information.
'devenv.exe': Loaded 'C:\Qt\4.6.2\bin\QtCore4.dll', Binary was not built with debug information.
First-chance exception at 0x77747e52 in devenv.exe: 0xC0000139: Entry Point Not Found.
'devenv.exe': Unloaded 'C:\Python26\Lib\site-packages\PyQt4\QtGui.pyd'
'devenv.exe': Unloaded 'C:\Qt\4.6.2\bin\QtCore4.dll'

It looks like it's trying to load another module after QtCore4.dll, but fails. Any ideas why this might be happening?

Answer 1

After some investigation, it appears that my C++ app is using Qt dlls from one install of Qt, and Python is trying to load different Qt dlls - the ones installed with PyQt. I suspect that the failure is happening because the same process is trying to two dlls that are mostly the same.