Testing if a Python executable was detected, gracefully

Hello everybody,

I'm writing unit tests for code that calls some Python scripts. Early on, I would like to test whether MATLAB can find a valid Python executable. Naturally, the function to use in this case is `pyversion` - however, the documentation does not specify the expected outputs in case an executable is not found. I'm assuming these are empty strings/char arrays, but have no way of verifying that.

Another approach that would likely work is just trying to use the interface (with a fallback):

try
  py.None; % or many other constants/functions that work when python is set up correctly
  % ... it works
catch
  % ... it doesn't work
end

However, this makes me cringe a little, since I'd rather avoid `try/catch` if there's an `if/else` that can achieve the same.

Can you please suggest a graceful non-windows-specific way to test if the current instance of MATLAB is able to interface with Python?

[Adam]

>> stuff = pyversion

stuff =

0×0 empty char array

This seems to work fine to test an ampty string.

[Dev-iL]

Hi Adam - thank you for trying that! Which OS+MATLAB release did you get this on?

[Adam]

Windows 10 R2017a

Answer 1

[Fangjun Jiang]

Did you check "doc pyversion"?

The syntax is there:

[version, executable, isloaded] = pyversion

[Dev-iL]

Of course I checked it - it is also mentioned in the question.