Generador de passwords usando Cadenas de Markov

Markov.py

import numpy
import sys
import string
import random

class Markov:
	def __init__(self):
		self.P = {}

	def Parse(self, filename):
		for line in open(filename):
			word = line.split()[-2]

			char1 = char2 = ""
			for current_char in word:
				self.P.setdefault((char1, char2), []).append(current_char)
		                char1 = char2
		                char2 = current_char
		
	def Generate(self, N=1000, lenght=None):
		# Si no se especifica ningun tamanio en particular
		# vamos generar el tamanio de cada password de acuerdo
		# a la distribucion empirica que obtuvimos analizando
		# la muestra de 400k passwords
		mu = 6
		sigma = 2

		if lenght == None:
			lenght = map(int, numpy.random.normal(mu, sigma, N))

		else:
			lenght = [lenght] * N

		G = []

		for i in xrange(0, N):
			password = ""
			c1, c2 = random.choice(self.P.keys())
	    
			for i in xrange(lenght[i]):
				try:
					c3 = random.choice(self.P[(c1, c2)])
				except KeyError:
					c1, c2 = random.choice(self.P.keys())
					c3 = c1

				password += c3
				c1 = c2
				c2 = c3
	
			G.append(password)

		return G