has_python(enable) parameter

This is one-point of truth/action for clarity

Author: scivision

+stdlib/+python/has_psutil.m

@@ -1,18 +1,12 @@
 %% PYTHON.HAS_PSUTIL is Python psutil module availble
 
-function y = has_psutil(force_old)
-if nargin < 1
-  force_old = false;
-end
-
-y = false;
+function y = has_psutil()
 
-% For MATLAB versions older than R2022a, skip Python version check unless force_old is true
-if stdlib.matlabOlderThan('R2022a') && ~force_old
-  return
+try
+  py.psutil.version_info();
+  y = true;
+catch
+  y = false;
 end
 
-y = pvt_psutil();
-% this is to avoid Matlab < R2022a JIT but with Python in general
-
 end

+stdlib/+python/private/pvt_psutil.m

@@ -109,14 +109,20 @@
 
       switch functionName
         case {'filesystem_type', 'is_removable', 'ram_total', 'ram_free', 'uptime'}
-          if ~stdlib.python.has_psutil(); continue, end
+          if ~stdlib.has_python() || ~stdlib.python.has_psutil()
+            continue
+          end
         case {'cpu_load', 'get_owner', 'get_process_priority', 'get_uid'}
           if ispc(), continue, end
         case 'is_admin'
           if ispc() && stdlib.matlabOlderThan('R2024a'), continue, end
         case 'is_dev_drive'
-          pyv = stdlib.python_version();
-          if any(pyv(1:2) < [3, 12]), continue, end
+          if stdlib.has_python()
+            pyv = stdlib.python_version();
+            if isempty(pyv) || any(pyv(1:2) < [3, 12])
+              continue
+            end
+          end
       end
     case 'native'
 

+stdlib/Backend.m

@@ -2,18 +2,17 @@
 %
 % https://www.mathworks.com/support/requirements/python-compatibility.html
 
-function y = has_python()
+function y = has_python(enable_check)
 
-try  %#ok<TRYNC>
-  r = matlabRelease();
-  if ispc && r.Release == "R2026a" && r.Stage == "prerelease"
-    % avoid python due to bug
-    y = false;
-    return
-  end
+y = false;
+
+if nargin == 0
+  enable_check = ~stdlib.matlabOlderThan('R2022a');
 end
 
-y = ~isempty(stdlib.python_version());
+if enable_check
+  y = ~isempty(stdlib.python_version());
+end
 
 end
 

+stdlib/has_python.m

@@ -1,7 +1,7 @@
 %% MATLABOLDERTHAN compare Matlab release name only e.g. R2025a
 % works for Matlab >= R2016b
 %
-% our simpler checks is about 200x faster than isMATLABReleaseOlderThan(release)
+% our implementation is about 200x faster than isMATLABReleaseOlderThan(release)
 
 function isOlder = matlabOlderThan(release)
 assert(nargin == 1, 'Specify Matlab release like ''R2025a''')

+stdlib/matlabOlderThan.m

@@ -14,10 +14,7 @@
 % where the environment has changed since pyenv() was set. For example
 % HPC with 'module load python3...'
 
-function [v, msg] = python_version(force_old)
-if nargin < 1
-  force_old = false;
-end
+function [v, msg] = python_version()
 
 persistent stdlib_py_version pyv_cached
 
@@ -36,10 +33,6 @@
 
 v = [];
 
-if stdlib.matlabOlderThan('R2022a') && ~force_old
-  return
-end
-
 % glitchy Python load can error on sys.version_info
 % if pyenv() hasn't ever been configured, may get uncatchable error
 % bad lexical cast: source type value could not be interpreted as target