code: def count_left_node(root):
      if root is None:
          return 0
      elif root.left is None:
          return count_left_node(root.right)
      else:
          return (
              1
              + count_left_node(root.left)
              + count_left_node(root.right)
          )
  
file_path: keon-algos/algorithms/tree/bst/count_left_node.py
imports: import unittest
  from bst import Node
  from bst import bst
label_desc: Use image node_id 1 for calling a global function with example usage: count_left_node(root) and returns: int, count_left_node, unknown