getattr

This question already has an answer here: How to access object attribute given string corresponding to name of that attribute 2 answers I have and object with an pseudo or special attribute that can be named in three different ways (Note: I don't control the code which generates the object) The value in the attributes (depending which one is set) is exactly the same, and I need to get that for further processing, so depending of the source of data, I can have something like: >>> obj.a 'value' >>> obj.b Traceback (most recent call last): File "<stdin>", line 1, in <module> AttributeError: Obj

I'd like to be able to do something like this: from dotDict import dotdictify life = {'bigBang': {'stars': {'planets': []} } } dotdictify(life) # This would be the regular way: life['bigBang']['stars']['planets'] = {'earth': {'singleCellLife': {}}} # But how can we make this work? life.bigBang.stars.planets.earth = {'singleCellLife': {}} #Also creating new child objects if none exist, using the following syntax: life.bigBang.stars.planets.earth.multiCellLife = {'reptiles':{},'mammals':{}} My motivations are to improve the succinctness of the code, and if possible use similar syntax to

I have a class like: class MyClass: Foo = 1 Bar = 2 Whenever MyClass.Foo or MyClass.Bar is invoked, I need a custom method to be invoked before the value is returned. Is it possible in Python? I know it is possible if I create an instance of the class and I can define my own __getattr__ method. But my scnenario involves using this class as such without creating any instance of it. Also I need a custom __str__ method to be invoked when str(MyClass.Foo) is invoked. Does Python provide such an option? Matt Anderson __getattr__() and __str__() for an object are found on its class, so if you want

I am trying to understand the difference between __getattr__ and __getattribute__ , however, I am failing at it. The answer to the Stack Overflow question Difference between __getattr__ vs __getattribute__ says: __getattribute__ is invoked before looking at the actual attributes on the object, and so can be tricky to implement correctly. You can end up in infinite recursions very easily. I have absolutely no idea what that means. Then it goes on to say: You almost certainly want __getattr__ . Why? I read that if __getattribute__ fails, __getattr__ is called. So why are there two different

I want to override access to one variable in a class, but return all others normally. How do I accomplish this with __getattribute__ ? I tried the following (which should also illustrate what I'm trying to do) but I get a recursion error: class D(object): def __init__(self): self.test=20 self.test2=21 def __getattribute__(self,name): if name=='test': return 0. else: return self.__dict__[name] >>> print D().test 0.0 >>> print D().test2 ... RuntimeError: maximum recursion depth exceeded in cmp Egil You get a recursion error because your attempt to access the self.__dict__ attribute inside _