def __new__(cls, *args, **kwargs): if not hasattr(ToastDialog, "_instance"): with ToastDialog._instance_lock: if not hasattr(ToastDialog, "_instance"): ToastDialog._instance = QDialog.__new__(cls) return ToastDialog._instance
def __new__(cls,**kwargs): # just can exits one instance from each modal that inherit this class if cls.__instance is None : cls.__instance = QDialog.__new__(cls) QDialog.__init__(cls.__instance,kwargs["Parent"]) return cls.__instance