Calling Python from Matlab / Can I use Python installed by Anaconda? / "NULL pointer returned from Python."

Would love to use some Python code a colleague wrote. I already have Anaconda installed, so I really don't want to install another version of Python (and associated libraries).

Tried:

pe = ...

pyenv('Version',...

fullfile('e:\', 'anaconda3', 'python.exe'));

myPythonVersion = pe.Version

py.print("Hello, Python!")

Got:

>> pe = ...

pyenv('Version',...

fullfile('e:\', 'anaconda3', 'python.exe'));

myPythonVersion = pe.Version

py.print("Hello, Python!")

myPythonVersion =

"3.8"

NULL pointer returned from Python.

>> py

>> pe

pe =

PythonEnvironment with properties:

Version: "3.8"

Executable: "e:\anaconda3\python.exe"

Library: "e:\anaconda3\python38.dll"

Home: "e:\anaconda3"

Status: NotLoaded

ExecutionMode: OutOfProcess

>>

Matlab Version R2020a (happy to upgrade, just too lazy right now...)

Answer 1

[Brian]

Not sure what the best answer is for this issue.

Due to other circumstances, I needed to re-install Matlab and Anaconda. Now everything works:

>> pe = ...

pyenv('Version',...

fullfile('c:\', 'temp', 'anaconda3', 'python.exe'));

>> py.print("Hello, Python!")

Hello, Python!

Is this due to:

• Re-installing Matlab?
• Installing the latest version of Matlab (R2022b)?
• Re-installing Anaconda?
• Putting Anaconda on the C:\ ?

sorry, I don't know.

What I do know is that launching from the Anaconda prompt is not required.

Answer 2

[Al Danial]

Try this start-up sequence: first open an Anaconda Prompt or Anaconda PowerShell terminal. Then within that terminal window, type the path to the matlab executable (or is it a launch .bat file on Windows?). Or just type 'matlab' if it is in your system-wide search path.

Then within matlab just do

>> pyenv

with no arguments to see if matlab figured everything out on its own.

[Simon Mwakitabu]

This worked fine for me too. When anaconda launches Matlab, it directs it to a pathfile which has pyhton libraries in anaconda.

[Hiren]

this worked for me too, thank you.