Interrogate/Interrogate_module outside dependencies

C++ coding using Panda3D
1

This question feels a bit awkward, like it’s simultaneously small enough to just be asked on the discord but at the same time I feel what I need to ask would make sense without a bit of background information attached, so here we go.

I’m using interrogate to generate c++ wrappers for a custom class that derives from ActorNode, which in turn derives from PhysicalNode.
When I initially compiled the pyd file and tried to test it I was met with this error:

file "boxToolNeo.py", line 14, in <module>
     from gamecode.acrossGame.playerEntityBase import *
NameError: name 'PhysicalNode' is not defined

After a little research I discovered from here the -import command for Interrogate_module. After a little more expirementation, I discovered that if I use -import panda3d.physics everything works perfectly.

I do worry about this though, since this would probably import the entirety of panda3d.physics instead of the components that are actually utilized. I of course tried something like -import panda3d.physics.ActorNode but this got me a much more vague error.

does anyone happen to know of a cheaper way of dealing with this sort of problem?

Thanks,

JAMS

EDIT: this might have something to do with the fact that interrogate’ s only generating an init/pyinit function for the library, and not the module. For now, I’ll treat that as a separate issue.
Double Edit: I forgot to mention that importing panda3d.core resolves the actornode dependency, but not the actornode’s own dependency of physicalnode.

2

After not working on this problem because of well… work, I’ve discovered the obvious: if I just import the dependencies before I import the custom class I don’t need to import the entirety of panda3d.physics.
like this:

from panda3d.physics import PhysicalNode
from <customClassLib> import *

it’s not clean, but it at the very least works.

3

Ah ha! I just realized that while it might be annoying to import those two dependencies every time I import my class, that doesn’t mean I have to every time I create a copy of said class!

I can just manually import the dependencies once in a python file where I declare a function that will set up and return a copy of my class, as well as doing a little behind the scenes work.

Then, I can just call the function from another file, requiring just a single import for the “manager” function.

4

There’s no difference in this regard between importing panda3d.physics and panda3d.physics.ActorNode; both will cause the entire panda3d.physics module to be loaded into memory, because it’s a single module and loading a module partially is not possible in Python. However, in no case will from <customClassLib> import * cause ActorNode to be added to the module namespace.

5

I didn’t know this! Thank you so much for telling me.
It’s probably a good thing that in exactly one month from now I’ll be taking a proper python course as opposed to teaching myself, so hopefully I won’t make quite as many mistakes such as this.