Question

为了帮助序列化为JSON，我通常构建一个继承自python dict类的类。如果该类应该具有特定的字段，我希望有方法来获取＆amp;集。

目前，我构建了一个类：

class MyRequest(dict):
    def __init__(self, firstName=None, lastName=None):
        self['firstName'] = firstName
        self['lastName'] = lastName

    def get_firstName(self):
        return self['firstName']
    def set_firstName(self, firstName):
        self['firstName'] = firstName

    def get_lastName(self):
        return self['lastName']
    def set_lastName(self, lastName):
        self['lastName'] = lastName

但这真的很麻烦。由于底层的“存储”是一个字典，我不能只访问像

这样的字段

myReq.firstName = "Foo"
print myReq.lastName

但是有没有办法到达那里，同时仍然保持dict支持？

Answer 1

怎么样：

class MyRequest(dict):
    def __init__(self, firstName=None, lastName=None):
        self['firstName'] = firstName
        self['lastName'] = lastName

    def __getattr__(self, name):
        return self[name]

    def __setattr__(self, name, value):
        self[name] = value

请注意，如果您的某个属性与dict方法具有相同的名称（例如update），则可能会再次困扰您。在这种情况下，获取属性将返回该方法，设置它将覆盖该方法。这可能很难调试。

Answer 2

是的，有办法做你想做的事。使用属性：

class MyRequest(dict):
    def __init__(self, firstName=None, lastName=None):
        self['firstName'] = firstName
        self['lastName'] = lastName

    @property
    def firstName(self):
        return self['firstName']

    @firstName.setter
    def firstName(self, firstName):
        self['firstName'] = firstName

    @property
    def lastName(self):
        return self['lastName']

    @lastName.setter
    def lastName(self, lastName):
        self['lastName'] = lastName

request = MyRequest('John', 'Connor')
print request.firstName, request.lastName
request.firstName = 'Sarah'
print request.firstName, request.lastName

继承dict的python类的getter / setter

2 个答案: