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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def validate(cpf_number):
 """This function validates a CPF number. This function uses calculation package to calculate both digits and then validates the number. :param cpf_number: a CPF number to be validated. Only numbers. :type cpf_number: string :return: Bool -- True for a valid number, False otherwise. """


    _cpf = compat.clear_punctuation(cpf_number)

    if (len(_cpf) != 11 or
       len(set(_cpf)) == 1):
        return False

    first_part = _cpf[:9]
    second_part = _cpf[:10]
    first_digit = _cpf[9]
    second_digit = _cpf[10]

    if (first_digit == calc.calculate_first_digit(first_part) and
       second_digit == calc.calculate_second_digit(second_part)):
        return True

    return False