Tree branches. Defines a tree as a tuple and then access the branches with 0 based index, the nesting is defined as another tuple.

tree_branches.py

import math
def tree_ref(tree, index):
    if(isinstance(index,(list,tuple)) and (len(index)>1)):
        #print tree
        #print index
        #print "--1---"
        newTree =  tree[index[0]]
        #print newTree
        newIndex = tuple([index[k] for k in range(1,len(index))])
        #print newIndex
        #print "-----2------"
        return tree_ref(newTree, newIndex)
    else:
        if(isinstance(index,(list,tuple))):
            return tree[index[0]]
        else:
            return tree[index]