Python: how to determine if a node is a ROP node

[jonp]

Maybe I'm missing it, as I only searched for about 10 minutes, but how does one determine if a node is of type hou.RopNode?

For example, the rop_alembic SOP node is of type "rop_alembic", but its category is "Sop".  How do I determine that it's actually a render node?

One possible answer is to do this:

is_rop = hasattr(node, 'render')

...but that can give false positives.

 

-Jon

[Atom]

The term "rop" does appear in the type. You can string search for it. Or simply try to reference a common known parameter only on the ROP. If it errors out it is not a ROP.

[jonp]

That is true, but when I try to access 'geometry()' on that node, it will raise an error that mentions it being a 'hou.RopNode' class!  How do I get to that type definition myself?  That seems like the magic bullet.

[f1480187]

There is misleading collision between Python types and Houdini operator types. In Houdini terms (by calling hou.Node.type() method), rop_geometry is a Sop node, also true inside Operator Type Manager window:

In Python terms, this node will be an instance of hou.RopNode, no matter where it is:

isinstance(node, hou.RopNode)
type(node) == hou.RopNode

Before now, I was sure that every node within one network will be same type for both Houdini and Python.

Edited December 4, 2016 by f1480187

[jonp]

Yes!  isinstance() or type().  Guess I wasn't being idiomatic enough in my thinking.

Thanks!