binary tree.py

def check_binary_search_tree_(root):
    nodes = [root]
    isTreeValid = True
    while len(nodes) != 0:
        currentNodes = [i for i in nodes]
        nodes.clear()
        for node in currentNodes:
            print("node data is " + str(node.data))
            if node.left != None:
                print("node left data is " + str(node.left.data))
            if node.right != None:
                print("node right data is " + str(node.right.data))
            if node.left != None and node.left.data > node.data:
                return False
            if node.right != None and node.right.data < node.data:
                return False
            if node.left != None:
                nodes.append(node.left)
            if node.right != None:
                nodes.append(node.right)
    return isTreeValid