Embedded Python

Embedding a Python interpreter within openCFS is triggered via

See the presentation for detailed introduction for developers cfs_python.pdf

configure and test

• enable USE_EMBEDDED_PYTHON to build
• cmake has a strange logic to select a Python instance. In case use something like

 set(PYTHON_INCLUDE_DIR "/Users/fwein/.pyenv/versions/3.8.1/include/python3.8")
 set(PYTHON_LIBRARY "/Users/fwein/.pyenv/versions/3.8.1/lib/libpython3.8.a")

• test via ctest -R python

Anaconda

• For Windows it is a good idea to use Anaconda.
• If python complains about missing activation, call e.g. c:\ProgramData\Anaconda3\Scripts\activate base
• If embedded python fails with error below, the reason could be a non-existing c:\ProgramData\Anaconda3\python39.zip in sys.path. Fix it by creating a file of that name (content does not matter, e.g. a text file with 'conda installation is poor´.

Python path configuration:
  PYTHONHOME = (not set)
  PYTHONPATH = (not set)
  program name = 'python'
  isolated = 0
  environment = 1
  user site = 1
  import site = 1
  sys._base_executable = 'C:\\Users\\fwein\\code\\master\\release_ninja\\bin\\cfstest.exe'
  sys.base_prefix = 'c:\\ProgramData\\Anaconda3'
  sys.base_exec_prefix = 'c:\\ProgramData\\Anaconda3'
  sys.platlibdir = 'lib'
  sys.executable = 'C:\\Users\\fwein\\code\\master\\release_ninja\\bin\\cfstest.exe'
  sys.prefix = 'c:\\ProgramData\\Anaconda3'
  sys.exec_prefix = 'c:\\ProgramData\\Anaconda3'
  sys.path = [
    'c:\\ProgramData\\Anaconda3\\python39.zip',
    '.\\DLLs',
    '.\\lib',
    'C:\\Users\\fwein\\code\\master\\release_ninja\\bin',
  ]
Fatal Python error: init_fs_encoding: failed to get the Python codec of the filesystem encoding
Python runtime state: core initialized
ModuleNotFoundError: No module named 'encodings'