def shrink(self, node: Node):
"""
Shrink sub-tree into one node.
Args:
node (Node): List of nodes to be merged.
"""
node_name = node.identifier
parent_node = self[node.predecessor(self.tree_identifier)]
# Keep successors of parent.
brothers = deepcopy(parent_node.successors(self.tree_identifier))
child = node.successors(self.tree_identifier)[0]
self.move_node(source=child,
destination=node.predecessor(self.tree_identifier))
self.remove(node)
brothers[brothers.index(node_name)] = child
parent_node.set_successors(brothers, tree_id=self.tree_identifier)
def shrink(self, node: Node):
"""
Shrink sub-tree into one node.
Use child node to replace its ancestor.
Args:
node (Node): List of nodes to be merged.
"""
node_name = node.identifier
parent_node = self[node.predecessor(self.tree_identifier)]
# Keep successors of parent.
brothers = deepcopy(parent_node.successors(self.tree_identifier))
# Because shrink occurs when node has only one child,
# so we take index-0.
child = node.successors(self.tree_identifier)[0]
self.move_node(source=child,
destination=node.predecessor(self.tree_identifier))
self.remove(node)
brothers[brothers.index(node_name)] = child
parent_node.set_successors(brothers, tree_id=self.tree_identifier)
class NodeCase(unittest.TestCase):
def setUp(self):
self.node1 = Node("Test One", "identifier 1")
self.node2 = Node("Test Two", "identifier 2")
def test_initialization(self):
self.assertEqual(self.node1.tag, "Test One")
self.assertEqual(self.node1.identifier, "identifier 1")
# retro-compatibility
self.assertEqual(self.node1.bpointer, None)
self.assertEqual(self.node1.fpointer, [])
self.assertEqual(self.node1.expanded, True)
self.assertEqual(self.node1._predecessor, {})
self.assertEqual(self.node1._successors, defaultdict(list))
self.assertEqual(self.node1.data, None)
def test_set_tag(self):
self.node1.tag = "Test 1"
self.assertEqual(self.node1.tag, "Test 1")
self.node1.tag = "Test One"
def test_object_as_node_tag(self):
node = Node(tag=(0, 1))
self.assertEqual(node.tag, (0, 1))
self.assertTrue(node.__repr__().startswith('Node'))
def test_set_identifier(self):
self.node1.identifier = "ID1"
self.assertEqual(self.node1.identifier, "ID1")
self.node1.identifier = "identifier 1"
def test_set_fpointer(self):
# retro-compatibility
self.node1.update_fpointer("identifier 2")
self.assertEqual(self.node1.fpointer, ['identifier 2'])
self.node1.fpointer = []
self.assertEqual(self.node1.fpointer, [])
def test_update_successors(self):
self.node1.update_successors("identifier 2", tree_id="tree 1")
self.assertEqual(self.node1.successors("tree 1"), ['identifier 2'])
self.assertEqual(self.node1._successors["tree 1"], ['identifier 2'])
self.node1.set_successors([], tree_id="tree 1")
self.assertEqual(self.node1._successors["tree 1"], [])
def test_set_bpointer(self):
# retro-compatibility
self.node2.update_bpointer("identifier 1")
self.assertEqual(self.node2.bpointer, 'identifier 1')
self.node2.bpointer = None
self.assertEqual(self.node2.bpointer, None)
def test_set_predecessor(self):
self.node2.set_predecessor("identifier 1", "tree 1")
self.assertEqual(self.node2.predecessor("tree 1"), 'identifier 1')
self.assertEqual(self.node2._predecessor["tree 1"], 'identifier 1')
self.node2.set_predecessor(None, "tree 1")
self.assertEqual(self.node2.predecessor("tree 1"), None)
def test_set_is_leaf(self):
self.node1.update_fpointer("identifier 2")
self.node2.update_bpointer("identifier 1")
self.assertEqual(self.node1.is_leaf(), False)
self.assertEqual(self.node2.is_leaf(), True)
def test_tree_wise_is_leaf(self):
self.node1.update_successors("identifier 2", tree_id="tree 1")
self.node2.set_predecessor("identifier 1", "tree 1")
self.assertEqual(self.node1.is_leaf("tree 1"), False)
self.assertEqual(self.node2.is_leaf("tree 1"), True)
def test_data(self):
class Flower(object):
def __init__(self, color):
self.color = color
def __str__(self):
return "%s" % self.color
self.node1.data = Flower("red")
self.assertEqual(self.node1.data.color, "red")
