I think a better example to show why you might want a ?. operator would involve nested lookups. If you have something like node.child.attribute.value, handling potential Nones at each lookup with ifs would get very verbose very quickly (and that verbosity would be bad, as it would make it much harder to make out the main point of the code).

You could surround the nested lookups in try/except and catch the AttributeError, but that could mask other errors - for instance, if you misspelled the name of one of the nested attributes (arguably, it would be better if trying to look up an attribute on None raised a different exception, rather than AttributeError).

I don't think the existing pythonic way is not too verbose:

   if node and node.child and node.child.attribute: 
      …

for nested loop you can do

   for child in node.children or []:
      for attrib in child.attributes or []:
         …

That's generally considered unpythonic though. A more pythonic way to write that is

    for child in node.children if node.children else []:
        for attrib in child.attributes if child.attributes else []:
            ...

Which, granted, is a lot more verbose and probably not any more readable but at least it's not abusing the or operator.

This is subtly incorrect. Correctly, it should be:

    libpaths = paths.split(":") if paths is not None else []

or else falsey values of paths (0, [], False) can still cause an error.

If your path variable is set to 0, [], False then it's best to fail early anyways.