Sum of Path Numbers (medium)

class TreeNode:
  def __init__(self, val, left=None, right=None):
    self.val = val
    self.left = left
    self.right = right
def find_sum_of_path_numbers(root):
  return find_root_to_leaf_path_numbers(root, 0)
def find_root_to_leaf_path_numbers(currentNode, pathSum):
  if currentNode is None:
    return 0
  # calculate the path number of the current node
  pathSum = 10 * pathSum + currentNode.val
  # if the current node is a leaf, return the current path sum
  if currentNode.left is None and currentNode.right is None:
    return pathSum
  # traverse the left and the right sub-tree
  return find_root_to_leaf_path_numbers(currentNode.left, pathSum) + find_root_to_leaf_path_numbers(currentNode.right, pathSum)
def main():
  root = TreeNode(1)
  root.left = TreeNode(0)
  root.right = TreeNode(1)
  root.left.left = TreeNode(1)
  root.right.left = TreeNode(6)
  root.right.right = TreeNode(5)
  print("Total Sum of Path Numbers: " + str(find_sum_of_path_numbers(root)))
main()

tab = 0
# Display List Code Below:
def height(node):
  if (node == None):
    return 0
  return 1 + max(height(node.left), height(node.right))
def draw_node(output, link_above, node, level, p, link_char):
  if (node == None):
    return
  out = "["
  h = len(output)
  SP = " "
  if (p < 0):
    for s in output:
      if (s):
        s = " "*(-1*p) + s
    for s in link_above:
      if (s):
        s = " "*(-1*p) + s
  if level < h - 1:
    p = max(p, len(output[level + 1]))
  if (level > 0):
    p = max(p, len(output[level - 1]))
  p = max(p, len(output[level]))
  # Fill in to left
  if (node.left):
    leftData = SP + str(node.left.val) + SP
    draw_node(output, link_above, node.left,
          level + 1, p - len(leftData), 'L')
    p = max(p, len(output[level + 1]))
  # Enter this data
  space = p - len(output[level])
  if (space > 0):
    output[level] += (' ' * space)
  node_data = SP + str(node.val) + SP
  output[level] += node_data
  # Add vertical link above
  space = p + len(SP) - len(link_above[level])
  if (space > 0):
    link_above[level] += (' ' * space)
  link_above[level] += link_char
  # Fill in to right
  if (node.right):
    draw_node(output, link_above, node.right,
          level + 1, len(output[level]), 'R')
def display_tree(root):
  if (root == None):
    print("\tNone")
  h = height(root)
  output = []
  link_above = []
  for i in range(0, h):
    output.append("")
    link_above.append("")
  draw_node(output, link_above, root, 0, 5, ' ')
  # Create link lines
  for i in range(h):
    for j in range(len(link_above[i])):
      if (link_above[i][j] != ' '):
        size = len(output[i - 1])
        if (size < j + 1):
          output[i - 1] += " " * (j + 1 - size)
        jj = j
        if (link_above[i][j] == 'L'):
          while (output[i - 1][jj] == ' '):
            jj += 1
          for k in range(j+1, jj-1):
            str1 = output[i - 1]
            list1 = list(str1)
            list1[k] = '_'
            output[i - 1] = ''.join(list1)
        elif(link_above[i][j] == 'R'):
          while (output[i - 1][jj] == ' '):
            jj -= 1
          # k = j-1
          for k in range(j-1, jj+1, -1):
            temp = output[i - 1]
            list1 = list(temp)
            list1[k] = '_'
            output[i - 1] = ''.join(list1)
            k = k - 1
        str1 = link_above[i]
        list1 = list(str1)
        list1[j] = '|'
        link_above[i] = ''.join(list1)
  # Output
  for i in range(h):
    if (i):
      print("\t", link_above[i])
    print("\t", output[i])
class TreeNode:
  def __init__(self, val, left=None, right=None):
    self.val = val
    self.left = left
    self.right = right
def find_sum_of_path_numbers(root):
  return find_root_to_leaf_path_numbers(root, 0)
def find_root_to_leaf_path_numbers(currentNode, pathSum):
  global tab
  tab += 1
  if currentNode is None:
    print(tab*"\t" + "Current node: None")
    print(tab*"\t" + "Returning pathSum = 0")
    print("")
    return 0
  # calculate the path number of the current node
  print(tab*"\t" + "Current node value: ", currentNode.val, sep="")
  print(tab*"\t" + "pathSum = 10 * ", pathSum, " + ", currentNode.val, " = ",10 * pathSum + currentNode.val,  sep="")
  pathSum = 10 * pathSum + currentNode.val
  print("")
  # if the current node is a leaf, return the current path sum
  if currentNode.left is None and currentNode.right is None:
    print(tab*"\t" + "At the leaf node --> returning pathSum: ", pathSum, sep="")
    print("")
    return pathSum
  # traverse the left and the right sub-tree
  print(tab*"\t" + "Recursive call to the left subtree of node ", currentNode.val)
  x = find_root_to_leaf_path_numbers(currentNode.left, pathSum)
  tab -=1
  print(tab*"\t" + "Recursive call to the right subtree of node ", currentNode.val)
  y = find_root_to_leaf_path_numbers(currentNode.right, pathSum)
  tab -=1
  print(tab*"\t" + "Adding pathSum from the left and right subtree: ", x, " + ", y, " = ", x+y, sep = "")
  print("")
  return x + y
def main():
  root = TreeNode(1)
  root.left = TreeNode(0)
  root.right = TreeNode(1)
  root.left.left = TreeNode(1)
  root.right.left = TreeNode(6)
  root.right.right = TreeNode(5)
  root2 = TreeNode(10)
  root2.left = TreeNode(3)
  root2.right = TreeNode(4)
  root2.right.left = TreeNode(1)
  input = [root, root2]
  for i in input:
    print("Input tree:")
    display_tree(i)
    print("Total Sum of Path Numbers: " +
        str(find_sum_of_path_numbers(root)))
    print(("-"*100)+"\n")
    global tab
    tab = 0
main()