class BinaryTreeVertex:
'''vertex controls for the BST'''
def __init__(self, value):
    self.right = None
    self.left = None
    self.value = value


...
def total_Depth(self):
    print ("val:", self.value)
    if self.left and self.right:
        return (self.left.total_Depth()) + 1 and (self.right.total_Depth()) + 1
    elif self.left:
        return 1 + self.left.total_Depth()
    elif self.right:
        return 1 + self.right.total_Depth()
    else:
        return 1
...
tree = BinarySearchTree()
arr = [6,10,20,8,3]
for i in arr:
    tree.insert(i)
tree.searchPath(20)
print (tree.total_Depth())