MATLAB Engine API for Python 3.7

I am trying to call a Matlab script from my Python script. I have installed the MATLAB Engine API for Python. I am using 64-bit version of Matlab and Python. I am using Python 3.7.4. Which, accoding to this, should be supported:

https://www.mathworks.com/help/matlab/matlab_external/system-requirements-for-matlab-engine-for-python.html

However, when I try to compile this code:

import matlab.engine
eng = matlab.engine.start_matlab()
eng.main(nargout=0)

I get these error messages:

Traceback (most recent call last):
  File "C:\Users\psvendsen\AppData\Local\Programs\Python\Python37\lib\site-packages\matlab\engine\__init__.py", line 45, in <module>
    pythonengine = importlib.import_module("matlabengineforpython"+_PYTHONVERSION)
  File "C:\Users\psvendsen\AppData\Local\Programs\Python\Python37\lib\importlib\__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
  File "<frozen importlib._bootstrap>", line 983, in _find_and_load
  File "<frozen importlib._bootstrap>", line 965, in _find_and_load_unlocked
ModuleNotFoundError: No module named 'matlabengineforpython3_7'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\psvendsen\AppData\Local\Programs\Python\Python37\lib\site-packages\matlab\engine\__init__.py", line 61, in <module>
    pythonengine = importlib.import_module("matlabengineforpython"+_PYTHONVERSION)
  File "C:\Users\psvendsen\AppData\Local\Programs\Python\Python37\lib\importlib\__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
  File "<frozen importlib._bootstrap>", line 983, in _find_and_load
  File "<frozen importlib._bootstrap>", line 967, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 670, in _load_unlocked
  File "<frozen importlib._bootstrap>", line 583, in module_from_spec
  File "<frozen importlib._bootstrap_external>", line 1043, in create_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
ImportError: DLL load failed: The parameter is incorrect.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\psvendsen\OneDrive - Revision Military\Desktop\Python-Matlab Bridge\main.py", line 10, in <module>
    import matlab.engine
  File "C:\Users\psvendsen\AppData\Local\Programs\Python\Python37\lib\site-packages\matlab\engine\__init__.py", line 64, in <module>
    'MathWorks Technical Support for assistance: %s' % e)
OSError: Please reinstall MATLAB Engine for Python or contact MathWorks Technical Support for assistance: DLL load failed: The parameter is incorrect.
[Finished in 0.8s]

Any idea what is wrong?

[iSinnerman]

I've solved this by using Python 3.6.8

One search showed that you need to be using the same bit versions of Matlab and Python, e.g. both 32 bit or both 64 bit. I checked my Matlab version and it was 64 bit. I was using Python 3.7 64 bit so I then decided to try Python 3.6.8 and it all went as per the API install instructions on the Matlab site. I also found that I had to install Python with the custom options (as per another post), install as system administrator -> custom options -> additionally check for all users and add python to environment variables -> install. You can check if Python is installed as Matlab needs it to be installed, by typing python at the command prompt in windows and see if it starts python properly.

Answer 1

[Peter Svendsen]

I found the solution on another site:

Matlab kernel also should be install.

pip install matlab_kernel 

Then in file /usr/local/lib/python3.7/site-packages/matlab/engine/__init__.py comment raise EnvironmentError("Python %s is not supported." % _version) and add _PYTHONVERSION = 3_6. In result:

if _version in _supported_versions: 
    _PYTHONVERSION = _version 
else: 
    _PYTHONVERSION = '3_6' 
    #raise EnvironmentError("Python %s is not supported." % _version)

[Mike Ross]

I am running MATLAB 2017a and Python 3.7.4 (both 64-bit), and I ran into similar problems with not being able to successfully import matlab.engine in Python. I tried the above solution, but now when I try to import matlab.engine in Python, I see the following error message:

  File "/usr/local/lib/python3.7/site-packages/IPython/core/interactiveshell.py", line 3326, in run_code
    exec(code_obj, self.user_global_ns, self.user_ns)
  File "<ipython-input-1-754f7d50ef2a>", line 1, in <module>
    import matlab.engine
  File "/home/mross/Downloads/pycharm-community-2018.3.4/helpers/pydev/_pydev_bundle/pydev_import_hook.py", line 21, in do_import
    module = self._system_import(name, *args, **kwargs)
  File "/usr/local/lib/python3.7/site-packages/matlab/engine/__init__.py", line 83
    def start_matlab(option="-nodesktop", async=False):
                                              ^
SyntaxError: invalid syntax

I read that "async" is a reserved variable name in Python 3.7. Has anyone else encountered this or know of a solution to get import matlab.engine working?

Thanks in advance.

[Peter Svendsen]

Sorry, I don't know. I did not get that error.

[quanli]

Dear sir

Have you solved the error? I encountered the same error.

Answer 2

[Dmitry Boltyanskiy]

I have moved the operator

import matlab.engine

to the first row of script and this make good result.

Before that the script worked under IDE PyCharm. But the script was showing this Error when I launched in terminal.

[wallflower]

Same for me. Thanks !