CPF Generator V3

import random, json

class CPFGen(object):
    def __init__(self):
        self.cpf = []
        index = 10

        for i in range(9):
            digit = random.randint(0, 9)
            self.cpf.append(digit)

        for i in range(2):
            self.verificator(index)
            index += 1

        self.cpf.insert(3, ".")
        self.cpf.insert(7, ".")
        self.cpf.insert(11, "-")

        string = ""

        for i in range(len(self.cpf)):
            string += str(self.cpf[i])

        self.generated_cpf = string

    def verificator(self, index):
        sum = 0
        for i in range(len(self.cpf), 0, -1):
            sum += index * self.cpf[i - 1]
            index -= 1

        if sum % 11 <= 2:
            digit = 0
        else:
            digit = 11 - (sum % 11)

        self.cpf.append(digit)

with open("CPFs.txt", "w") as file:
    data = {}
    for i in range(1000000):
        cpf = CPFGen()
        data[f"{i + 1}"] = cpf.generated_cpf
        print(f'{i + 1}°: {data[f"{i + 1}"]}')
    json_object = json.dumps(data)
    file.write(json_object)