Python new-style-class相关问题

Question

我是一名 Python 学习者，目前正在编写一个字段数量可变的类，如 "Bunch of Named Stuff" example here 中所示。 .

class Bunch:
    def __init__(self, **kwds):
        self.__dict__.update(kwds)

我还想在这个类中写一个__setattr__ 来检查输入的属性名。但是，python documentation说，

If __setattr__() wants to assign to an instance attribute, it should not simply execute "self.name = value" -- this would cause a recursive call to itself. Instead, it should insert the value in the dictionary of instance attributes, e.g., "self.__dict__[name] = value". For new-style classes, rather than accessing the instance dictionary, it should call the base class method with the same name, for example, "object.__setattr__(self, name, value)".

在那种情况下，我是否也应该在 __init__ 函数中使用 object.__dict__ 来替换 self.__dict__？

Answer 1

你可以使用

class Bunch:
    def __init__(self, **kwds):
        self.__dict__.update(kwds)

    def __setattr__(self, name, value):
        #do your verification stuff
        self.__dict__[name] = value

或使用新式类:

class Bunch(object):
    def __init__(self, **kwds):
        self.__dict__.update(kwds)

    def __setattr__(self, name, value):
        #do your verification stuff
        super(Bunch, self).__setattr__(name, value)