How to access attributes and methods of a component directly?

Question

Having created a composite class in python, is there a (simple) way how to directly access the attributes/methods of the components? That is without specifying which component the attribute/method belongs to?

Here is the MWE:

class Component1:
    def __init__(self, data1):
        self.data1 = data1

    def add1(self):
        return self.data1 + 1

class Component2:
    def __init__(self, data2):
        self.data2 = data2

    def add2(self):
        return self.data2 + 2



class Composite:
    def __init__(self, data1, data2):
        self.component1 = Component1(data1)
        self.component2 = Component2(data2)


composite = Composite(data1, data2)

# Now I can access data1 (and data2)
# But it is really cumbersome
composite.component1.data1



# So I would like to have just
composite.data1

Is there a way to achieve this especially when the number of attributes and methods is high? I know I could add the property

@property
def data1(self):
    return self.component1.data1

but that would be painful with a high number of attributes and methods.

Edit:

Each component has different attributes/method names from each other. There also is not a common basis (eg, Component1().comp1_attibute_i or anything similar). The number at the end of the names is not present in the real problem (it was used just for simplification).

You would at the very least need to have a way to map out that `component1` has attribute `data1`. If all the subfields had the same name, you could iterate all the attributes of `Composite` and then access their common attribute. Without a common name though, I can't see how you could automate this without assuming something like the first found attribute is the one you're after. Unless you assume that any attribute ending in `1` has a sub-attribute ending in `1`, but that would be a bit of a fragile naming scheme I think. — Carcigenicate, Jun 02 '21 at 15:52
@Carcigenicate: I have edited the question to clarify the naming conventions. If I understand you correctly, there is no way to "flatten" the hierarchy without providing a map? Could you point me to a direction how does this map would look like? And many thanks for a quick answer! Thank you for a quick answer. — user64150, Jun 03 '21 at 13:22
If you find yourself needing to access the components more often than the composite, it calls into question whether you need the composite in the first place. — chepner, Jun 03 '21 at 13:22
@user64150 You could try to use the `__dict__` attribute of `Composite`. You could do a recursive flatten of each object's `__dict__` to get a flat dictionary of all attributes. That strikes me as a bit hacky and expensive though. I don't know of a clean, cheap way to achieve what you're after. — Carcigenicate, Jun 03 '21 at 13:25
@chepner: The 1st component defines an optimization problem, the 2nd solves the optimization, and the 3rd computes outputs based on the optimization outcome (think of R2 after running an OLS). I thought it makes sense to wrap it up into a single class to have it all together, since it belongs together. But I am happy to use a diffent structure if it would make more sense — user64150, Jun 03 '21 at 13:32
Just because the three things are related doesn't mean you need to model that with a class. Are there any operations that require any interaction? It doesn't seem like your class does anything a simple tuple couldn't handle. — chepner, Jun 03 '21 at 13:36

score 0 · Answer 1 · answered Jun 02 '21 at 16:37

Derive or use dictionaries for your class. One dictionary has the attributes, and one dictionary the methods.

So attribute access is composite["data1"].

Functions could be invoked via getattr. I don't know the details but there's some useful stuff here.

How to access attributes and methods of a component directly?

Edit:

1 Answers1