identical python

# http://code2begin.blogspot.com
# Program to check if 2 given trees are identical to each other
# node class
class node:
    def __init__(self, element):
        self.data = element
        self.left = None
        self.right = None


# function to check if 2 given trees are identical to each other
def isIdentical(root1, root2):
    # if both the nodes are null then return True
    if root1 is None and root2 is None:
        return True

    # if the node are not null then check
    # 1. do nodes have same data
    # 2. do the have identical left subtrees
    # 3. do the have identical right subtrees
    if root1 is not None and root2 is not None:
        return (
            root1.data == root2.data and
            isIdentical(root1.left, root2.left) and
            isIdentical(root1.right, root2.right)
        )
    return False


head = node(1)
head.left = node(2)
head.right = node(3)
head.left.left = node(4)
head.left.right = node(5)
head.right.right = node(6)
head.left.left.right = node(7)
head.right.right.left = node(8)
head.left.left.right.left = node(9)
head.left.left.right.left.left = node(10)
head.right.right.left.right = node(11)

head2 = node(5)
head2.left = node(2)
head2.right = node(12)
head2.left.left = node(-4)
head2.left.right = node(3)
head2.right.left = node(9)
head2.right.right = node(21)
head2.right.right.left = node(19)
head2.right.right.right = node(25)

head3 = node(1)
head3.left = node(2)
head3.right = node(3)
head3.left.left = node(4)
head3.left.right = node(5)
head3.right.right = node(6)
head3.left.left.right = node(7)
head3.right.right.left = node(8)
head3.left.left.right.left = node(9)
head3.left.left.right.left.left = node(10)
head3.right.right.left.right = node(11)

print("TREE #1 and TREE #2 are identical : " + str(isIdentical(head, head2)))
print("TREE #1 and TREE #3 are identical : " + str(isIdentical(head, head3)))