import re


nondigit = re.compile('\D');


def validate_cpf(cpf):
	global nondigit

	cpf = nondigit.sub('', cpf)
	if len(cpf) < 11:
		raise Exception("CPF inválido")

	vcode = [] # verification digit
	for count in range(2):
		count += 1

		aux = [num for num in range(2, 10 + count)]
		aux.reverse()
		cpflist = [int(digit) for digit in cpf]
		digit = 11 - sum(map(lambda tp: tp[0] * tp[1], zip(cpflist, aux))) % 11
		digit = digit if digit <= 9 else 0
		vcode.append(str(digit))
	vcode = ''.join(vcode)

	if vcode != cpf[-2:]:
		raise Exception("CPF inválido")

	return True