更新 Object 的数据成员

Question

I have been trying to update only those members of an object passed into a function which are truthy but I feel like my approach is bad for updating them.

Here's my approach:

class A:

    def __init__(self, name, age, _id):

        # Data Members

        self.name = name
        self.age = age
        self._id = _id

    def update(self, name=None, age=None, _id=None):

        # These need to be updated if the parameters are truthy

        if name:
            self.name = name
        if age:
            self.age = age
        if _id:
            self._id = _id

It looks okay-ish if the members are less but If more members need to be updated, it becomes a mess.

How can this approach be improved?

Answer 1

Take the parameters as a dictionary and loop over it.

def update(self, **kwargs):
    for name, val in kwargs.items():
        setattr(self, name, val)

BTW, checking for truthy values is not a good idea if legitimate values can be falsey (eg setting an attribute to 0 ). It would be better to use if name is not None: -- this just assumes that None is not a legitimate value.

Full code:

class A:

    def __init__(self, name, age, _id):

        # Data Members

        self.name = name
        self.age = age

    def update(self, **kwargs):
        for name, val in kwargs.items():
            setattr(self, name, val)

foo = A("Barry", 59, 1234)
foo.update(name = "Joe", age = 10)
print(foo.name)