Hello Spirello,
I assume if you named your function add_node_v10 it's because you're running 10.x LTM and you have install bigsuds.
As I'm running 11.x LTM instance I can not test the following code, but,
I think you have to pass list as parameters to the create function,
as said in the documentation (https://devcentral.f5.com/wiki/iControl.LocalLB__NodeAddress__create.ashx)
the prototype is:
create(
in String [] node_addresses,
in long [] limits
);
Syntax "String [] node_addresses" mean "list of String", where "String" is a node_address
With your sample you should send
lb_obj.LocalLB.NodeAddress.create(['192.168.100.100'], [0])
By the way, as the return type of create function is "void", so you will not print anything 😉