A Krita script to lock all leaf layers

main.py

from krita import Krita

def lock_leaves(node):
    children = node.childNodes()
    
    if children:
        node.setLocked(False)
        
        for child in children:
            lock_leaves(child)
    else:
        node.setLocked(True)
        
nodes = Krita.instance().activeDocument().topLevelNodes()

for node in nodes:
    lock_leaves(node)