Printing a Tree data structure in Python

Question

I was looking for a possible implementation of tree printing, which prints the tree in a user-friendly way, and not as an instance of object.

I came across this solution on the net:

source: http://cbio.ufs.ac.za/live_docs/nbn_tut/trees.html

class node(object):
    def __init__(self, value, children = []):
        self.value = value
        self.children = children

    def __repr__(self, level=0):
        ret = "\t"*level+repr(self.value)+"\n"
        for child in self.children:
            ret += child.__repr__(level+1)
        return ret

This code prints the tree in the following way:

'grandmother'
    'daughter'
        'granddaughter'
        'grandson'
    'son'
        'granddaughter'
        'grandson'

Is it possible to have the same result but without changing the __repr__ method, because I am using it for another purpose.

EDIT:

Solution without modifying __repr__ and __str__

def other_name(self, level=0):
    print '\t' * level + repr(self.value)
    for child in self.children:
        child.other_name(level+1)

Answer 1

Why don't you store it as a treelib object and print it out similar to how we print the CHAID tree out here with more relevant node descriptions related to your use case?

([], {0: 809, 1: 500}, (sex, p=1.47145310169e-81, chi=365.886947811, groups=[['female'], ['male']]))
??? (['female'], {0: 127, 1: 339}, (embarked, p=9.17624191599e-07, chi=24.0936494474, groups=[['C', '<missing>'], ['Q', 'S']]))
?   ??? (['C', '<missing>'], {0: 11, 1: 104}, <Invalid Chaid Split>)
?   ??? (['Q', 'S'], {0: 116, 1: 235}, <Invalid Chaid Split>)
??? (['male'], {0: 682, 1: 161}, (embarked, p=5.017855245e-05, chi=16.4413525404, groups=[['C'], ['Q', 'S']]))
    ??? (['C'], {0: 109, 1: 48}, <Invalid Chaid Split>)
    ??? (['Q', 'S'], {0: 573, 1: 113}, <Invalid Chaid Split>)