ModuleNotFound in model linearization

[PT-Traviresta]

OMPython/OMPython/__init__.py

Line 1751 in bd17a66

from linearized_model import linearized_model

I ran a script file and had the problem of ModuleNotFound when importing linearized_model.

My solution is to modify __init__.py and append the analysis folder to sys.path

sys.path.append(os.path.dirname(linearFile))
from linearized_model import linearized_model

[arun3688]

@PT-Traviresta usually it should not be problem because the session is running in the directory where the linearized file is created

[PT-Traviresta]

@arun3688

If I run the script line-by-line in the interactive mode, there's no problem. But if I run it in the script mode, the error occurs.

My colleague also faced the same problem.

[arun3688]

@PT-Traviresta the issue is fixed with this commit 59ff73b, Thanks for the contribution, i will close this issue, please open the issue in case you face any problem

[martinscripts]

I get the same error on python 3.13.2 with OMPython 3.6.0

[adeas31]

@syntron can you please test this. I believe this should work in master after the changes you have done.

[syntron]

@martinscripts could you please re-test with the latest version? This should not happen at all as the linearized file is no longer imported!

For the old version - 3.6.0 - the error is still valid as the change was merged after this!

[martinscripts]

Hey @syntron,

I am on v3.6.0 and python 3.13.2 and in OMPython's pyproject.toml it says version = "3.6.0", so that seems to be the latest one?

Which version should I install instead?

here my mwe:

from OMPython import OMCSessionZMQ
from OMPython import ModelicaSystem
omc = OMCSessionZMQ()
model_path=omc.sendExpression("getInstallationDirectoryPath()") + "/share/doc/omc/testmodels/"

mod1 = ModelicaSystem(model_path + "BouncingBall.mo","BouncingBall")
mod1.linearize()

output:

SyntaxError Traceback (most recent call last)
File c:\Users\mfranke\Documents\projects\general_python\.venv\Lib\site-packages\OMPython\__init__.py:1776, in ModelicaSystem.linearize(self, lintime, simflags)
 1773 try:
 1774 ## do not add the linearfile directory to path, as multiple execution of linearization will always use the first added path, instead execute the file
 1775 ## https://github.com/OpenModelica/OMPython/issues/196
-> [1776](file:///C:/Users/mfranke/Documents/projects/general_python/.venv/Lib/site-packages/OMPython/__init__.py:1776) module = importlib.machinery.SourceFileLoader("linearized_model", linearFile).load_module()
 1777 result = module.linearized_model()

File <frozen importlib._bootstrap_external>:680, in _check_name_wrapper(self, name, *args, **kwargs)

File <frozen importlib._bootstrap_external>:1207, in load_module(self, fullname)

File <frozen importlib._bootstrap_external>:1031, in load_module(self, fullname)

File <frozen importlib._bootstrap>:537, in _load_module_shim(self, fullname)

File <frozen importlib._bootstrap>:966, in _load(spec)

File <frozen importlib._bootstrap>:935, in _load_unlocked(spec)

File <frozen importlib._bootstrap_external>:1022, in exec_module(self, module)

File <frozen importlib._bootstrap_external>:1160, in get_code(self, fullname)
...
-> [1786](file:///C:/Users/mfranke/Documents/projects/general_python/.venv/Lib/site-packages/OMPython/__init__.py:1786) raise Exception("ModuleNotFoundError: No module named 'linearized_model'")
 1787 else:
 1788 errormsg = self.getconn.sendExpression("getErrorString()")

Exception: ModuleNotFoundError: No module named 'linearized_model'

[adeas31]

By latest version we mean installing OMPython from latest source https://github.com/OpenModelica/OMPython?tab=readme-ov-file#via-source

[martinscripts]

ok, thanks.

I did pip install git+https://github.com/OpenModelica/OMPython.git now, which I assume should do the same?

With the same mwe from above, I now get

ModelicaSystemError Traceback (most recent call last)
Cell In[1], [line 7](vscode-notebook-cell:?execution_count=1&line=7)
 4 model_path=omc.sendExpression("getInstallationDirectoryPath()") + "/share/doc/omc/testmodels/"
 6 mod1 = ModelicaSystem(model_path + "BouncingBall.mo","BouncingBall")
----> [7](vscode-notebook-cell:?execution_count=1&line=7) mod1.linearize()
 9 # plt.plot([1,2,3])
 10 # plt.savefig('test_before.png')
 11 # plt.show()
 (...) 15 # plt.savefig('test_after.png')
 16 # plt.show()

File c:\Users\mfranke\Documents\projects\general_python\.venv\Lib\site-packages\OMPython\ModelicaSystem.py:1672, in ModelicaSystem.linearize(self, lintime, simflags, simargs, timeout)
 1669 linear_file = self.getWorkDirectory() / "linearized_model.py"
 1670 linear_file.unlink(missing_ok=True)
-> [1672](file:///C:/Users/mfranke/Documents/projects/general_python/.venv/Lib/site-packages/OMPython/ModelicaSystem.py:1672) returncode = om_cmd.run()
 1673 if returncode != 0:
 1674 raise ModelicaSystemError(f"Linearize failed with return code: {returncode}")

File c:\Users\mfranke\Documents\projects\general_python\.venv\Lib\site-packages\OMPython\ModelicaSystem.py:279, in ModelicaSystemCmd.run(self)
 277 path_bat = self._runpath / f"{self._model_name}.bat"
 278 if not path_bat.exists():
--> [279](file:///C:/Users/mfranke/Documents/projects/general_python/.venv/Lib/site-packages/OMPython/ModelicaSystem.py:279) raise ModelicaSystemError("Batch file (*.bat) does not exist " + str(path_bat))
 281 with open(file=path_bat, mode='r', encoding='utf-8') as fh:
 282 for line in fh:

ModelicaSystemError: Batch file (*.bat) does not exist C:\Users\mfranke\AppData\Local\Temp\tmph422rspr\BouncingBall.bat

[adeas31]

@syntron is this because of some latest changes in working directory handling? The model.bat file should be created.

@martinscripts any idea which OpenModelica version you are using? Can you show us which files are generated in C:\Users\mfranke\AppData\Local\Temp\tmph422rspr

[arun3688]

@martinscripts i guess you are using older OpenModelica version, if i remember it correctly OpenModelica 1.23 or earlier version generates linearization file with different pattern, I guess the new changes might have removed the check for older openmodelica version i guess, if that is the case please install the latest openmodelica version and test it

[martinscripts]

Hey, yes, you are right, I am on OM 1.18, so quite old.
I am not able to test it with the new versin right now, but I find your explanation plausible. If it persists for newer versions in the future, we can still reconvene.
Thank you and best regards