CMake: Permit to explictly specify Python installation directory (#218)

CHANGELOG.md

@@ -7,6 +7,7 @@ The format of this document is based on [Keep a Changelog](https://keepachangelo
 
 ### Changed
 * Enable publishing of robot joints in ROS 2 via `controlBoard_nws_ros2` for `iCubGazeboV2_5_visuomanip` (https://github.com/robotology/icub-models/pull/211).
+* CMake: Permit to explictly specify Python installation directory by setting the `ICUB_MODELS_PYTHON_INSTALL_DIR` CMake variable (https://github.com/robotology/icub-models/pull/218).
 
 ### Fixed
 * Fixed wrong simulated finger hall effect sensors port names prefix for `iCubGazeboV2_5_visuomanip` (https://github.com/robotology/icub-models/pull/215).

python/CMakeLists.txt

@@ -11,20 +11,23 @@ if(ICUB_MODELS_USES_PYTHON)
     FALSE)
 
     # Install the resulting Python package for the active interpreter
-    if(ICUB_MODELS_DETECT_ACTIVE_PYTHON_SITEPACKAGES)
-        set(PYTHON_INSTDIR ${Python3_SITELIB}/icub_models)
-    else()
-      if(Python3_VERSION VERSION_GREATER_EQUAL 3.12)
-        execute_process(COMMAND ${Python3_EXECUTABLE} -c "import os;import sysconfig;relative_site_packages = sysconfig.get_path('purelib').replace(sysconfig.get_path('data'), '').lstrip(os.path.sep);print(relative_site_packages)"
-          OUTPUT_VARIABLE _PYTHON_INSTDIR)
+    if(NOT DEFINED ICUB_MODELS_PYTHON_INSTALL_DIR)
+      if(ICUB_MODELS_DETECT_ACTIVE_PYTHON_SITEPACKAGES)
+        set(ICUB_MODELS_PYTHON_INSTALL_DIR ${Python3_SITELIB})
       else()
-        execute_process(COMMAND ${Python3_EXECUTABLE} -c "from distutils import sysconfig; print(sysconfig.get_python_lib(1,0,prefix=''))"
-          OUTPUT_VARIABLE _PYTHON_INSTDIR)
+        if(Python3_VERSION VERSION_GREATER_EQUAL 3.12)
+          execute_process(COMMAND ${Python3_EXECUTABLE} -c "import os;import sysconfig;relative_site_packages = sysconfig.get_path('purelib').replace(sysconfig.get_path('data'), '').lstrip(os.path.sep);print(relative_site_packages)"
+            OUTPUT_VARIABLE _PYTHON_INSTDIR)
+        else()
+          execute_process(COMMAND ${Python3_EXECUTABLE} -c "from distutils import sysconfig; print(sysconfig.get_python_lib(1,0,prefix=''))"
+            OUTPUT_VARIABLE _PYTHON_INSTDIR)
+        endif()
+        string(STRIP ${_PYTHON_INSTDIR} _PYTHON_INSTDIR_CLEAN)
+        set(ICUB_MODELS_PYTHON_INSTALL_DIR ${_PYTHON_INSTDIR_CLEAN})
       endif()
-
-      string(STRIP ${_PYTHON_INSTDIR} _PYTHON_INSTDIR_CLEAN)
-      set(PYTHON_INSTDIR ${_PYTHON_INSTDIR_CLEAN}/icub_models)
     endif()
+    set(PYTHON_INSTDIR ${ICUB_MODELS_PYTHON_INSTALL_DIR}/icub_models)
+
 
 
     # Install the __init__.py file