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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 fingerprint(self):
 """ Creates a fingerprint that can be compared with a public key to see if the two form a pair. This fingerprint is not compatible with fingerprints generated by any other software. :return: A byte string that is a sha256 hash of selected components (based on the key type) """


        if self._fingerprint is None:
            params = self['private_key_algorithm']['parameters']
            key = self['private_key'].parsed

            if self.algorithm == 'rsa':
                to_hash = '%d:%d' % (
                    key['modulus'].native,
                    key['public_exponent'].native,
                )

            elif self.algorithm == 'dsa':
                public_key = self.public_key
                to_hash = '%d:%d:%d:%d' % (
                    params['p'].native,
                    params['q'].native,
                    params['g'].native,
                    public_key.native,
                )

            elif self.algorithm == 'ec':
                public_key = key['public_key'].native
                if public_key is None:
                    public_key = self.public_key.native

                if params.name == 'named':
                    to_hash = '%s:' % params.chosen.native
                    to_hash = to_hash.encode('utf-8')
                    to_hash += public_key

                elif params.name == 'implicit_ca':
                    to_hash = public_key

                elif params.name == 'specified':
                    to_hash = '%s:' % params.chosen['field_id']['parameters'].native
                    to_hash = to_hash.encode('utf-8')
                    to_hash += b':' + params.chosen['curve']['a'].native
                    to_hash += b':' + params.chosen['curve']['b'].native
                    to_hash += public_key

            if isinstance(to_hash, str_cls):
                to_hash = to_hash.encode('utf-8')

            self._fingerprint = hashlib.sha256(to_hash).digest()

        return self._fingerprint