unable to import OMCSessionZMQ

[Yulu76]

I've tried to run a simple test on Spyder but it doesn't work:

from OMPython import OMCSessionZMQ
I got the error: ImportError: cannot import name 'OMCSessionZMQ'

For information, I've installed OMPython with the command below in the enviroment of Anaconda (py35):

cd %OPENMODELICAHOME%\share\omc\scripts\PythonInterface
python -m pip install .

And my OM version is 1.11.0.

Thanks a lot for your help!

[adeas31]

ZeroMQ is introduced in 1.12. You need to update your OpenModelica.

[Yulu76]

ZeroMQ is introduced in 1.12. You need to update your OpenModelica.

Is there a way to stay in 1.11 and use OMPython? Because the model I've received doen't simulate on 1.12 but only on 1.11. Thanks for your help.

[sjoelund]

from OMPython import OMCSession uses the older CORBA interface

[Yulu76]

from OMPython import OMCSession uses the older CORBA interface

When I do

from OMPython import OMCSession
omc = OMCSession()

I get this error :
ImportError: cannot import name 'CORBA'

Is CORBA supported by Python3? I'm using python3.5

[sjoelund]

It is, but you need to have installed omniidl and Python support for CORBA prior to running the pip install command so that it will generate the necessary files. This is quite easy to do on Linux, but is quite painful on Windows...

[Yulu76]

It is, but you need to have installed omniidl and Python support for CORBA prior to running the pip install command so that it will generate the necessary files. This is quite easy to do on Linux, but is quite painful on Windows...

So to recap, I'm using OM 1.11 (due to model restriction) and python 3.5 (anaconda) on Windows. I try to use OMPython to run several simulations with different parameter values. What would be the best option to install OMPython in your opinion?
Is there a tutoriel to install omniidl on Windows? Because passing to OM 1.12 is currently not an option for me.
Would it be easier if I go through FMU?

[sjoelund]

In my opinion the easiest way is to install (docker or WSL or a virtual machine) and run the Linux version of OpenModelica 1.11 on your Windows.

The ZeroMQ stuff is much easier to handle because Python has its native implementation of it that works well.

[Yulu76]

I removed OM v1.11 and installed v1.12. When I do

from OMPython import OMCSessionZMQ
I still get this error: AttributeError: module 'OMPython' has no attribute 'OMCSessionZMQ'

I think the problem might not be related to the version of OpenModelica but something else. Have you had this error before?

[adeas31]

Did you run pip install after installing v1.12?
What is the output of python -m pip install .? Maybe it has failed and python is still using the old OMPython.

[Yulu76]

I've just found the solution: after install OM v1.12 and OMPython, I had to install manuelly pyzmq in the repertory of PythonInterface using >> pip install pyzmq.
Now I can import successfully OMCSessionZMQ!

BUT an exception is raised when I do >> omc = OMCSessionZMQ( )
I got this error:
"OMC Server is down. Please start it! Log-file says: Le chemin d'accŠs sp‚cifi‚ est introuvable."
The exception is from
File "C:\Logiciels\anaconda3\envs\py35\lib\site-packages\OMPython_init_.py", line 528, in _connect_to_omc
raise Exception

[thorade]

Something is wrong. pip should have handled all dependencies, no need to install pyzmq manually.
Can you please rerun the following commands?
Either run

python -m pip install -U https://github.com/OpenModelica/OMPython/archive/master.zip

or run

cd %OPENMODELICAHOME%\share\omc\scripts\PythonInterface
python -m pip install -U .

Then, once you have done that, please run

python -m pip show ompython

and post the output here.

[Yulu76]

So I just ran

cd %OPENMODELICAHOME%\share\omc\scripts\PythonInterface
python -m pip install -U .

and

from OMPython import OMCSessionZMQ

This worked. But when I call OMCSessionZMQ() I still got the same exception raised:

`2018-11-22 13:53:22,700 - OMPython - ERROR - OMC Server is down. Please start it! Log-file says:
Le chemin d'accŠs sp‚cifi‚ est introuvable.

Traceback (most recent call last):

File "", line 1, in
omc = OMPython.OMCSessionZMQ()

File "C:\Logiciels\anaconda3\envs\py35\lib\site-packages\OMPython_init_.py", line 502, in init
self._connect_to_omc()

File "C:\Logiciels\anaconda3\envs\py35\lib\site-packages\OMPython_init_.py", line 528, in _connect_to_omc
raise Exception

Exception`

[thorade]

What does OpenModelicaHome point to?
And what is the output of pip show ompython?

[Yulu76]

and there's an slight error in the README.txt of OMPython, that was why the install didn't work for me in the first place:

cd %OPENMODELICAHOME%\share\omc\scripts\PythonInterface
python -m pip install .

But instead it should be:

python -m pip install -U .