docs: def guess_project_dir():
      """Find the top-level Django project directory.
  
      This function guesses the top-level Django project directory based on
      the current environment.  It looks for module containing the currently-
      active settings module, in both pre-1.4 and post-1.4 layours.
      """
      projname = settings.SETTINGS_MODULE.split(".",1)[0]
      projmod = import_module(projname)
      projdir = os.path.dirname(projmod.__file__)
  
      # For Django 1.3 and earlier, the manage.py file was located
      # in the same directory as the settings file.
      if os.path.isfile(os.path.join(projdir,"manage.py")):
          return projdir
  
      # For Django 1.4 and later, the manage.py file is located in
      # the directory *containing* the settings file.
      projdir = os.path.abspath(os.path.join(projdir, os.path.pardir))
      if os.path.isfile(os.path.join(projdir,"manage.py")):
          return projdir
  
      msg = "Unable to determine the Django project directory;"\
            " use --project-dir to specify it"
      raise RuntimeError(msg)