'Return the frequency count for this Lemma'

def lemma_count(self, lemma):

    if (lemma._lang != u'eng'):
        return 0
    if (self._key_count_file is None):
        self._key_count_file = self.open(u'cntlist.rev')
    line = _binary_search_file(self._key_count_file, lemma._key)
    if line:
        return int(line.rsplit(u'    ', 1)[(-1)])
    else:
        return 0
