我写的python单例 init会调用多次 如何解决?

Question

"init"输出三次

class ConfigLoader(object):    _instance = None    _lock = threading.Lock()    def __new__(cls, *args, **kw):        if cls._instance is None:            with cls._lock:                if cls._instance is None:                    cls._instance = object.__new__(cls)        return cls._instance    def __init__(self, config_file_name="config.json"):        print("init")        self.file_path = os.path.join(os.getcwd(), 'config', config_file_name)        self.json_data = Nonec1 = ConfigLoader(config_file_name="config.json")c2 = ConfigLoader()c3 = ConfigLoader()

Answer 1

object.__new__

If __new__() is invoked during object construction and it returns an instance of cls, then the new instance’s __init__() method will be invoked like __init__(self[, ...]), where self is the new instance and the remaining arguments are the same as were passed to the object constructor.

构造了三次，__init__ 就会被调用三次。