ngrams and their counts with 'bisect' python2

bisect_ngrams.py

import bisect

class WordList( object ):
    """Leaf-level is list of words and counts."""
    def __init__( self ):
        self.words= [ ('\xff-None-',0) ]
    def count( self, wordTuple ):
        assert len(wordTuple)==1
        word= wordTuple[0]
        loc= bisect.bisect_left( self.words, word )
        if self.words[loc][0] != word:
            self.words.insert( loc, (word,0) )
        self.words[loc]= ( word, self.words[loc][1]+1 )
    def getWords( self ):
        return self.words[:-1]

class WordTree( object ):
    """Above non-leaf nodes are words and either trees or lists."""
    def __init__( self ):
        self.words= [ ('\xff-None-',None)  ]
    def count( self, wordTuple ):
        head, tail = wordTuple[0], wordTuple[1:]
        loc= bisect.bisect_left( self.words, head )
        if self.words[loc][0] != head:
            if len(tail) == 1:
                newList= WordList()
            else:
                newList= WordTree()
            self.words.insert( loc, (head,newList) )
        self.words[loc][1].count( tail )
    def getWords( self ):
        return self.words[:-1]

t = WordTree()
for a in ( ('the','quick','brown'), ('the','quick','fox'),('hilary','clinton','obama') ):
    t.count(a)

for w1,wt1 in t.getWords():
    print w1
    for w2,wt2 in wt1.getWords():
        print w2
        for w3 in wt2.getWords():
            print w3