LeetCode-style binary tree deserializer and ASCII tree visualizer.
LeetCode uses a serialized format to represent binary trees using level order traversal where None values indicate path terminators (i.e. that no node is present in this possible child location).
This package provides a function leetcode_trees.binarytree.tree_from_list which builds a tree from a serialized list of node values and returns the root. This root node can then be used as inputs to functions expecting a standard tree representation with nodes node whose children are accessed using node.left and node.right, and whose value is stored in node.val.
This package also includes a simple ASCII-based binary tree visualizer which prints trees to the terminal.
>>> from leetcode_trees import binarytree
>>> tree = binarytree.tree_from_list(list(range(14)))
>>> binarytree.print_tree(tree)
________0_________
___1___ ____2____
_3_ _4__ _5__ _6
7 8 9 10 11 12 13
>>> tree2 = binarytree.tree_from_list(['A','B','C','D',None,'E',None,'F','G','H'])
>>> binarytree.print_tree(tree2)
_______A_______
___B ___C
_D_ _E
F G H
>>> tree3 = binarytree.tree_from_list(["you","can","also","have","node","values","with","longer","string",None,"representations"])
>>> binarytree.print_tree(tree3)
_____________you______________
______can______ _also__
_have___ node____ values with
longer string representations
>>> tree4 = binarytree.tree_from_list(['A','B',None,None,'C','D','E','F'])
>>> binarytree.print_tree(tree4)
_______________A
B_______
___C___
_D E
F pip install git+https://github.com/cflamant/leetcode-trees.git
Alternatively, you can download the repository and copy the directory leetcode_trees into the directory you are working in.