def num_leaves ( tree ) : if tree . is_leaf : return 1 else : return num_leaves ( tree . left_child ) + num_leaves ( tree . right_child )
count node and children in tree python
Determine the number of leaves in a tree
def num_leaves(tree):
    """Determine the number of leaves in a tree"""
    if tree.is_leaf:
        return 1
    else:
        return num_leaves(tree.left_child) + num_leaves(tree.right_child)