code: def import_obj(clsname, default_module=None):
      
      if default_module is not None:
          if not clsname.startswith(default_module + '.'):
              clsname = '{0}.{1}'.format(default_module, clsname)
      mod, clsname = clsname.rsplit('.', 1)
      mod = importlib.import_module(mod)
      try:
          obj = getattr(mod, clsname)
      except AttributeError:
          raise ImportError('Cannot import {0} from {1}'.format(clsname, mod))
      return obj
docs: Import the object given by clsname.
      If default_module is specified, import from this module.