MATLAB Engine API for Python - ModuleNotFoundError
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Hi,
I'm struggling to install and use the Matlab Engine API for Python.
Python distribution: Winpython 3.8 64 bit
But when I try a simple
import matlab.engine
I get the following error:
>>>> import matlab.engine
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "C:\Users\lab.motori2\WPy64-38122\pypy3.8-v7.3.9-win64\lib\site-packages\matlabengineforpython-r2022a-py3.8.egg\matlab\__init__.py", line 214, in <module>
from matlabmultidimarrayforpython import double, single, uint8, int8, uint16, \
ModuleNotFoundError: No module named 'matlabmultidimarrayforpython'
Any help will be appreciated.
Thanks!
Accepted Answer
Kojiro Saito
on 31 May 2022
Edited: Kojiro Saito
on 6 Jun 2022
matlabmultidimarrayforpython.pyd will be found in $MATLAB_INSTALL\extern\engines\python\dist\matlab\engine\win64 folder.
Could you confirm the files? If not, your there might be an issue of MATLAB installation.
UPDATED
In some Python distributions, MATLAB Engine might not work well. If you can, how about try installing pure Python from python.org,
and try running setup install again?
In Command Prompt, run the following.
cd "$MATLAB_INSTALL\extern\engines\python"
C:\FULLPATH\TO\python.exe setup.py install --prefix="C:\Users\lab.motori2\WPy64-38122\pypy3.8-v7.3.9-win64\lib\site-packages\"
then, create a script,
test.py
import sys
sys.path.append("C:\Users\lab.motori2\WPy64-38122\pypy3.8-v7.3.9-win64\lib\site-packages\")
import matlab.engine
and execute from CPython.
C:\FULLPATH\TO\python.exe test.py
13 Comments
Leonardo Ricupero
on 31 May 2022
This is what I got on that folder:
Kojiro Saito
on 31 May 2022
OK. Could you show the full messages of "python setup.py install"?
Leonardo Ricupero
on 1 Jun 2022
Kojiro Saito
on 1 Jun 2022
There are several messages which will not occur in success installation.
How about installing by pip install?
pip install matlabengine==9.12
Leonardo Ricupero
on 1 Jun 2022
Kojiro Saito
on 1 Jun 2022
It says "[PyPy 7.3.9 with MSC v.1929 64 bit (AMD64)] on win32".
Could you tell us which environment is win32? Because MATLAB only supports 64bit Python environment.
Leonardo Ricupero
on 1 Jun 2022
Kojiro Saito
on 1 Jun 2022
So, could you try installing temporary pure Python from python.org,
and try running setup install again?
cd "$MATLAB_INSTALL\extern\engines\python"
C:\FULLPATH\TO\python.exe setup.py install --prefix="C:\Users\lab.motori2\WPy64-38122\pypy3.8-v7.3.9-win64\lib\site-packages\"
Leonardo Ricupero
on 1 Jun 2022
Kojiro Saito
on 2 Jun 2022
setup install seems to work well.
How about running the py code with CPython?
test.py
import sys
sys.path.append("C:\Users\lab.motori2\WPy64-38122\pypy3.8-v7.3.9-win64\lib\site-packages\")
import matlab.engine
C:\Users\lab.motori2\Python38\python.exe test.py
Leonardo Ricupero
on 6 Jun 2022
Kojiro Saito
on 6 Jun 2022
Thank you for your testing.
Some Python distributions work fine. I'm not sure what is the root cause of this issue in PyPy, but this page says, "The engine supports the reference implementation (CPython)", CPython is officially supported.
Leonardo Ricupero
on 6 Jun 2022
More Answers (1)
Ashwin Krishnakumar
on 19 Jun 2022
1 vote
Hello. I have the same error.
ModuleNotFoundError: No module named 'matlabmultidimarrayforpython'
This is the output when I run "python setup.py install --user" from the folder /Applications/MATLAB_R2021a.app/extern/engines/python . My installation folder.
It seems to install perfectly.
But when I run a script with the following error occurs. This is in a mac machine,
I do not however see .pyd file after matlab python engine.
Requesting your suggestions .
4 Comments
Makis
on 3 Jul 2022
i have the same problem
Ashwin Krishnakumar
on 3 Jul 2022
I did a small hack. Change the "matlabmultidimarrayforpython" to "mlarray"
This might be an hack that works for you. It worked for me.
Amanda
on 13 Oct 2022
If anyone encounters this error and your also get an import error with "mlarray". The issue is that with older Matlab installations (I encountered this with R2019a in both Linux and Windows), is that "mlarray" and "mlexceptions" is not located in the folders located in _ _arch.txt. To solve this, you need to edit "src/matlab/_ _ init _ _.py" :
+ sys.path.insert(0, os.path.dirname(os.path.dirname(engine_dir)))
+ from mlexceptions import ShareError, SizeError #and remove imports from mlarray
Gerlise
on 15 May 2023
Can you show me how your "src/matlab/__init__.py" looks like? I get the ModuleNotFoundErro: No module named "mlexceptions".
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