code: def import_string(impstr, attr=None):
      
      if "::" in impstr:
          impstr, attr = impstr.split("::")
      imported = wz_import_string(impstr)
      if attr is not None:
          return getobjpath(imported, attr)
      return imported
docs: Imports a string. Can import an attribute of the imported
      class/module using a double colon as a separator