Django - CPF Mask, DDD and phone number

I need to put a mask on entering the CPF, DDD and phone number. I'm a beginner in Python and Django and would like to know how I can display this mask at the time of typing:

For the CPF: 999.999.999-99.

For the Telephone: (99) 99999-9999.

I just created the models.py and admin.py files and as magic I already have functional forms, but I want to improve the presentation by putting the mask.

What do I have to do?

Where do I have to put this instruction?

I need some examples if I can.

models.py

class Cliente(models.Model):

    SEXO_CHOICES = (
        ('M', u'Masculino'),
        ('F', u'Feminino'),
    )

    ESTADO_CIVIL_CHOICES = (
        ('S', u'Solteiro'),
        ('C', u'Casado'),
        ('D', u'Divorciado'),
        ('V', u'Viúvo'),
    )

    nome = models.CharField(max_length=60)
    cpf = models.CharField(max_length=11, blank=True, null=True)
    dtNascimento = models.DateField(blank=True, null=True, verbose_name='Data de nascimento')
    sexo = models.CharField(max_length=1, choices=SEXO_CHOICES)
    estado_civil = models.CharField(max_length=1, choices=ESTADO_CIVIL_CHOICES, verbose_name='Estado civil')
    nrTelCelular = models.CharField(max_length=11, blank=True, null=True, verbose_name='Nº telefone celular')
    nrTelFixo = models.CharField(max_length=11, blank=True, null=True, verbose_name='Nº telefone fixo')

    def __str__(self):
        return self.nome

admin.py

class ClienteAdmin(admin.ModelAdmin):
    model = Cliente
    list_display = ['nome','cpf', 'dtNascimento', 'sexo',
                    'estado_civil', 'nrTelCelular', 'nrTelFixo']
    list_filter = ['sexo', 'estado_civil']
    search_fields = ['nome']
admin.site.register(Cliente, ClienteAdmin)