enhance stdlib.has_python checks

Check for non-compatible Python vs. Matlab

Author: scivision

+stdlib/private/pvt_python_version.m

@@ -4,7 +4,18 @@
 
 pe = pyenv();
 vs = pe.Version;
-if stdlib.strempty(vs), return, end
+if stdlib.strempty(vs)
+  return
+end
+
+% check with Python basic type to check this Python version is compatible with Matlab.
+% for example, Python 3.13 isn't compatible with Matlab R2025a, and this should catch that.
+% by PythonError ImportError: PyCapsule_Import could not import module "libmwbuffer"'
+try
+  py.tuple([1,1])
+catch
+  return
+end
 
 % this line may error like
 % "Python Error: TypeError: cannot create 'sys.version_info' instances"

Readme.md

@@ -46,7 +46,7 @@ Normally the user does not specify the backend as we prioritize faster backends.
   * Linux / macOS: R2024b and newer
 * [Java](./Readme_java.md): all supported Matlab releases
 * [Perl](https://www.mathworks.com/help/matlab/ref/perl.html):  Matlab R2018a and newer. This uses a system() call to Perl, which is bundled with Matlab on Windows and generally available on Linux and macOS
-* [Python](https://www.mathworks.com/help/matlab/call-python-libraries.html): Matlab R2022b and newer
+* [Python](https://www.mathworks.com/help/matlab/call-python-libraries.html): Matlab R2022b and newer. `stdlib.has_python` checks that the Python version set by `pyenv()` is compatible with the Matlab release.
 * System shell calls: all supported Matlab releases. As a backup when the platform doesn't have the primary (faster) methods available, the system shell can be called for some functions.
 
 ## Acknowledgments