CMake: Permit to explictly specify Python installation directory (#741)

This is done by setting the FRAMEWORK_PYTHON_INSTALL_DIR CMake variable.

CHANGELOG.md

@@ -13,6 +13,7 @@ All notable changes to this project are documented in this file.
 ### Changed
 - Remove the possibility to disable the telemetry in `System::AdvanceableRunner` (https://github.com/ami-iit/bipedal-locomotion-framework/pull/726)
 - Change implementation of classes used in `RobotDynamicsEstimator` to optimize performance (https://github.com/ami-iit/bipedal-locomotion-framework/pull/731)
+- CMake: Permit to explictly specify Python installation directory by setting the `FRAMEWORK_PYTHON_INSTALL_DIR` CMake variable (https://github.com/ami-iit/bipedal-locomotion-framework/pull/741)
 
 ## [0.15.0] - 2023-09-05
 ### Added

bindings/CMakeLists.txt

@@ -29,15 +29,18 @@ if(FRAMEWORK_COMPILE_PYTHON_BINDINGS)
         "Do you want BLF to detect and use the active site-package directory? (it could be a system dir)"
         FALSE)
 
-    # Install the resulting Python package for the active interpreter
-    if(FRAMEWORK_DETECT_ACTIVE_PYTHON_SITEPACKAGES)
-        set(PYTHON_INSTDIR ${Python3_SITELIB}/bipedal_locomotion_framework)
-    else()
-     execute_process(COMMAND ${Python3_EXECUTABLE} -c "from distutils import sysconfig; print(sysconfig.get_python_lib(1,0,prefix=''))"
-                     OUTPUT_VARIABLE _PYTHON_INSTDIR)
-     string(STRIP ${_PYTHON_INSTDIR} _PYTHON_INSTDIR_CLEAN)
-     set(PYTHON_INSTDIR ${_PYTHON_INSTDIR_CLEAN}/bipedal_locomotion_framework)
+    if(NOT DEFINED FRAMEWORK_PYTHON_INSTALL_DIR)
+      if(FRAMEWORK_DETECT_ACTIVE_PYTHON_SITEPACKAGES)
+        set(FRAMEWORK_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)
+        string(STRIP ${_PYTHON_INSTDIR} _PYTHON_INSTDIR_CLEAN)
+        set(FRAMEWORK_PYTHON_INSTALL_DIR ${_PYTHON_INSTDIR_CLEAN})
+      endif()
     endif()
+    set(PYTHON_INSTDIR ${FRAMEWORK_PYTHON_INSTALL_DIR}/bipedal_locomotion_framework)
+
 
     # Folder of the Python package within the build tree.
     # It is used for the Python tests.
@@ -63,15 +66,14 @@ if(FRAMEWORK_COMPILE_PYTHON_BINDINGS)
     set(BLF_PYTHON_PIP_METADATA_INSTALLER "cmake" CACHE STRING "Specify the string to identify the pip Installer. Default: cmake, change this if you are using another tool.")
     mark_as_advanced(BLF_PYTHON_PIP_METADATA_INSTALLER)
     if(BLF_PYTHON_PIP_METADATA_INSTALL)
-      get_filename_component(PYTHON_METADATA_PARENT_DIR ${PYTHON_INSTDIR} DIRECTORY)
       file(WRITE ${CMAKE_CURRENT_BINARY_DIR}/METADATA "")
       file(APPEND ${CMAKE_CURRENT_BINARY_DIR}/METADATA "Metadata-Version: 2.1${NEW_LINE}")
       file(APPEND ${CMAKE_CURRENT_BINARY_DIR}/METADATA "Name: bipedal_locomotion_framework${NEW_LINE}")
       file(APPEND ${CMAKE_CURRENT_BINARY_DIR}/METADATA "Version: ${BipedalLocomotionFramework_VERSION}${NEW_LINE}")
       file(WRITE ${CMAKE_CURRENT_BINARY_DIR}/INSTALLER "${BLF_PYTHON_PIP_METADATA_INSTALLER}${NEW_LINE}")
       install(
         FILES "${CMAKE_CURRENT_BINARY_DIR}/METADATA" "${CMAKE_CURRENT_BINARY_DIR}/INSTALLER"
-        DESTINATION ${PYTHON_METADATA_PARENT_DIR}/bipedal_locomotion_framework-${BipedalLocomotionFramework_VERSION}.dist-info)
+        DESTINATION ${FRAMEWORK_PYTHON_INSTALL_DIR}/bipedal_locomotion_framework-${BipedalLocomotionFramework_VERSION}.dist-info)
     endif()
 
 endif()