CODEWITHSUNDEEP
pythondictionary
Foobar
Foobar

Reputation: 76

python __setattr__ to act like __getattr__

I have a class that contains a dictionary, i use __getattr__(key) to get nicer access to the dictionary[key] now i would like to be able to set things in the dictionary with the same access style.

Class foo(object):
    def __init__(self, name):
        self.props = {"name":name}

    def __getattr__(self, attribute):
        return self.props[attribute]

This is so i can access it in this way

f = foo("test")
print f.name

I would like the ability to set the attributes aswell, however using setattr is proving problematic due to it being called before anything else fails. Is there a way to make it act like getattr?

Upvotes: 1

Views: 85

Answers (1)

Mariusz Jamro
Mariusz Jamro

Reputation: 31643

__setattr__ is fine, but you need to protect yourself from case when __setattr__ is called before self.props is set (RuntimeError: maximum recursion depth exceeded)

class foo(object):
    # List of properties which are not stored in the props dict
    __slots__ = ('props', 'other_property')

    def __init__(self, name):
        self.props = {"name":name}
        self.other_property = 2

    def __getattr__(self, attribute):
        return self.props[attribute]

    def __setattr__(self, name, value):
        if name in self.__slots__:
            super(foo, self).__setattr__(name, value)
        else:
            self.props[name] = value

f = foo("name")
print f.name
f.value = 2
f.name = "TEST"
print f.value
print f.props

Upvotes: 1

Related Questions