Test for empty nodepath

Scripting Issues
1

In Python, attempts to use any NodePath derivative as a boolean results in the error stating that this behavior is depreciated.

However, I can’t find any examples of how one is supposed to test for a NodePath’s existence. What’s the proper way for checking if a NodePath exists?

2

If bool(yourNodePath) or yourNodePath.isEmpty() (same thing) evaluate to false, you can call yourNodePath.getErrorType() to find out why it’s empty. It can be one of ETOk, ETNotFound, ETRemoved or ETFail.

3

The short answer is, the unambiguous way to test a NodePath return value is:

if not nodePath.isEmpty():
    # nodePath is valid
else:
    # nodePath is empty (failure case)

In the future, or if you put “empty-node-path future” in your Config.prc file, then you may also write the above test like this:

if nodePath:
    # nodePath is valid
else:
    # nodePath is empty (failure case)

David

4

Well, that makes sense, then. Thanks for the help you two!

The error type is especially useful info.