code: def import_name(mod_name):
      
      try:
          mod_obj_old = sys.modules[mod_name]
      except KeyError:
          mod_obj_old = None
  
      if mod_obj_old is not None:
          return mod_obj_old
  
      __import__(mod_name)
  
      mod_obj = sys.modules[mod_name]
  
      return mod_obj
docs: Import a module by module name.
  
      @param mod_name: module name.