Corrupted version of Matlab Engine for python on MacOSX 10.11

I used the Matlab Engine for Python a lot last fall, without any trouble. I just tried to reuse my old code today and I get the following error:

>>> import matlab.engine
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Library/Python/2.7/site-packages/matlab/engine/__init__.py", line 59, in <module>
    raise EnvironmentError('The installation of MATLAB Engine for Python is '
EnvironmentError: The installation of MATLAB Engine for Python is corrupted.  Please reinstall it or contact MathWorks Technical Support for assistance.

I am on MacOSX 10.11 (El Capitan), using Python 2.7 and Matlab 2015a. I reinstalled the Matlab Engine twice already, but no difference, I still get the same error.

Looking at the ini.py file, it seems that the line that fails is the following, yielding the error copied here:

>>> pythonengine = importlib.import_module("matlabengineforpython"+_PYTHONVERSION)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/importlib/__init__.py", line 37, in import_module
    __import__(name)
ImportError: dlopen(/Applications/MATLAB_R2015a.app/extern/engines/python/dist/matlab/engine/maci64/matlabengineforpython2_7.so, 2): Library not loaded: @rpath/libpython2.7.dylib
  Referenced from: /Applications/MATLAB_R2015a.app/extern/engines/python/dist/matlab/engine/maci64/matlabengineforpython2_7.so
  Reason: image not found

I have read a similar question where the answers pointed towards an issue with the libpython2.7.dylib HERE but I'm not sure I understand the solution. I can see the libpython2.7.dylib file in my /usr/lib/ folder.

[Cynthia Gerlein-Safdi]

It's looking like the re-install didn't actual replace the old files. Can I just get rid of the entire `matlab` folder in my `site-packages` folder to get a clean install?

[Cynthia Gerlein-Safdi]

I just removed the matlab folder from my site-packages folder and did a clean install of the engine. I still get the exact same error message.

Answer 1

[Bo Li]

The error message "Library not loaded: @rpath/libpython2.7.dylib" means that the Python library is not found or it is incompatible.

Would you try the solution that you already found?

http://www.mathworks.com/matlabcentral/answers/180518-why-does-matlab-engine-for-python-crash-when-using-a-non-system-default-version-of-python-on-mac

[Bo Li]

OK, the root cause could be that MATLAB R2015a is not supported on Mac OSX 10.11 base on following link:

http://www.mathworks.com/support/sysreq/roadmap.html

You probably need to install MATLAB R2015b or a later version in order to run Python Engine on this Mac OSX version.

[Cynthia Gerlein-Safdi]

Ok, I guess that makes sense. I'm almost certain I had already updated to 10.11 when the Engine was working last fall, but maybe I'm remembering wrong? I will try to update Matlab and see if it works. Thanks for the link!

[Cynthia Gerlein-Safdi]

Oh but wait, this table is just for Matlab in general, right? Matlab 2015a works fine on my computer right now... Why would the Engine not work if Matlab does?

Answer 2

[Bo Li]

What the version of Python? Python Engine from MATLAB R2015a works with CPython 2.7.12 from python.org on Mac OSX 10.11.

Answer 3

[Chong Zhao]

I highly suggest you to reinstall your Matlab. It works for me after I reinstall my Matlab and upgrade my python to the newest version (cause I have done these two things at the same time so I can't tell if both are needed or only one of it is needed).

Hope it works for you. :)