Сравнение дерева разбора и AST в питоне

tree.py

import parser
import symbol
import token
from pprint import pprint

print('parse tree:')

x = parser.expr('1 + 2 * 3')
y = x.tolist()

def humanize(x):
    for i, y in enumerate(x):
        if type(y) is int:
           x[i] = symbol.sym_name.get(y) or token.tok_name.get(y) or y
        try:
            humanize(y)
        except:
            pass

humanize(y)
pprint(y)

print('AST:')

import ast

tree = ast.parse('1 + 2 * 3')
pprint(ast.dump(tree))