From: Wander L. C. <wan...@gm...> - 2013-03-09 13:59:10
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2013/3/9 Mathieu Carette <mat...@gm...>: > Hello, > > I am trying to get pyusb working on OSX 10.8 with Python 2.7 (my goal is > to be able to communicate with a novation nocturn using python, see > https://github.com/dewert/nocturn-linux-midi which relies on pyusb.) > > I installed libusb 1.0 through macports > > $ port installed libusb -v > The following ports are currently installed: > libusb @1.0.9_0 (active) > libusb @1.0.9_0+universal > > Now after installing pyusb (and setting PYUSB_DEBUG_LEVEL = debug), it > seems pyusb cannot find any backend : > > >>> import usb > >>> usb.core.find() > 2013-03-09 10:28:47,635 ERROR:usb.backend.libusb1:Error loading libusb > 1.0 backend > Traceback (most recent call last): > File "/Library/Python/2.7/site-packages/usb/backend/libusb1.py", line > 655, in get_backend > _lib = _load_library() > File "/Library/Python/2.7/site-packages/usb/backend/libusb1.py", line > 205, in _load_library > raise OSError('USB library could not be found') > OSError: USB library could not be found > 2013-03-09 10:28:47,636 ERROR:usb.backend.openusb:Error loading OpenUSB > backend > Traceback (most recent call last): > File "/Library/Python/2.7/site-packages/usb/backend/openusb.py", line > 701, in get_backend > _lib = _load_library() > File "/Library/Python/2.7/site-packages/usb/backend/openusb.py", line > 248, in _load_library > raise OSError('USB library could not be found') > OSError: USB library could not be found > 2013-03-09 10:28:47,638 ERROR:usb.backend.libusb0:Error loading libusb > 0.1 backend > Traceback (most recent call last): > File "/Library/Python/2.7/site-packages/usb/backend/libusb0.py", line > 580, in get_backend > _setup_prototypes(_lib) > File "/Library/Python/2.7/site-packages/usb/backend/libusb0.py", line > 208, in _setup_prototypes > lib.usb_open.argtypes = [POINTER(_usb_device)] > File > "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/ctypes/__init__.py", > line 366, in __getattr__ > func = self.__getitem__(name) > File > "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/ctypes/__init__.py", > line 371, in __getitem__ > func = self._FuncPtr((name_or_ordinal, self)) > AttributeError: dlsym(RTLD_DEFAULT, usb_open): symbol not found > Traceback (most recent call last): > File "<stdin>", line 1, in <module> > File "/Library/Python/2.7/site-packages/usb/core.py", line 856, in find > raise ValueError('No backend available') > ValueError: No backend available > > > > Could anyone point me to the next thing to do in this case (I did search > the mailing list and the internet, where similar issues where occuring, > but I could not find an answer explicit enough for me to understand what > to do: I am rather new to both OSX and Python) > After you install libusb, where does it reside? -- Best Regards, Wander Lairson Costa |