(a)
tree.insert_node(parent, sibling, text, spacing=5,
                 pixmap_closed=None, mask_closed=None,
                 pixmap_opened=None, mask_opened=None,
                 is_leaf=TRUE, expanded=FALSE)

(b)
tree.freeze()
try:
    ...
finally:
    tree.thaw()

Example 1: (a) GtkCTree.insert_node default parameters; (b) GtkCTree and using the finally clause.