What does BDT stand for?

bdt.py

#!/usr/bin/env python2
import string
import random


class BDTGen(object):

    def __init__(self):
        self.words_dict = {
            letter: []
            for letter in string.letters
        }
        self.build_dict()
        self.random = random.SystemRandom()

    def build_dict(self, words_file='/usr/share/dict/words'):
        with open(words_file, 'r') as fp:
            for line in fp:
                word = line.strip().lower()
                letter = word[0]
                self.words_dict[letter].append(word)

    def random_word_by_letter(self, letter):
        return self.random.choice(self.words_dict[letter])

    def random_bdt(self):
        return ' '.join(map(self.random_word_by_letter, 'bdt'))

x = BDTGen()
for _ in range(20):
    print(x.random_bdt())

Sample output:

batterman diaclastic tornus
bisectrices denierer thalloid
biology dessertspoonful trophozooid
benzinduline dazingly thielaviopsis
beblotch designatum trancelike
bhat diastral thrombin
baboen disquantity therefore
bijugular dabbling thermophilic
birdcraft durham tephromyelitic
bertie dotkin throated
bufotalin diligentia tracheary
biolith decemdentate toran
boxkeeper disdainable trout
benchership demurrant tuboabdominal
biosociological denitrification tern
biometrical disturnpike thunderfish
bathylimnetic divertisement thomite
burred dissymmetrical takingly
biangulous dibasic trique