code: def project_workspace_addsitedir(sitedir):
      
      assert os.path.isdir(sitedir)
      try:
          from site import addsitedir
      except ImportError:
          # -- USE: Python2.7 site.py package
          from pysite import addsitedir
      next_package_pos = len(sys.path)
      addsitedir(sitedir)
  
      # -- POST-PROCESS: Move new packages from end to begin of sys.path list.
      pos = 0
      new_packages = sys.path[next_package_pos:]
      del sys.path[next_package_pos:]
      sys.path[pos:pos] = new_packages
docs: Similar to site.addsitedir() but prefers new sitedir over existing ones.
      Therefore, prefers local packages over installed packages.
  
      .. note::
          This allows to support *.pth files and zip-/egg-imports
          similar to an installed site-packages directory.