Dictionary-like behavior for components

[wpbonelli]

imod-python components act like dictionaries. You can use dictionary-style access to get and/or set a child component. We could follow this. And as @mjreno has pointed out, flopy3 lets you give packages arbitrary names. We want the same thing for flopy4, presumably.

[wpbonelli]

I see two ways to accomplish this

Our prototype currently has strongly-typed attributes. E.g. Gwf has an npf field, which is an Npf, and a Chd field, which is a list[Chd]. When you gwf.chd.append(...), the child is auto-named "chdN", where there were N items in the list before. But as stated above we want arbitrary naming.

Instead the model base class could have a packages field, a dict[str, Package]. Likewise for simulation with a models field, package with subpackages, etc. Then just implement MutableMapping to proxy it.

We could even "simulate" strong typing by inspecting the child types and setting dynamic attributes.

With this, though, the class is no longer fully self-describing — you can't read off its definition what its subcomponents are. We lose type-checking for the simulation structure. In effect we cut the edges in the spec tree and take responsibility for making sure people connect the nodes properly.

Alternatively we could invert 1), keep the strong typing, and and proxy dictionary access/modification to the data tree. If you gwf.chd.append(...) you still get the auto-naming, but if you gwf["my_chd"] = ... you get your name. And we can give our model base class a packages property (similarly models on a simulation) which just filters the data tree's children by type.

[wpbonelli]

closed by #130, it turned out 1) was not necessary, 2) was very simple