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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 spec(self, postf_un_ops: str) -> list: """Return prefix unary operators list"""

        spec = [(l + op, {'pat': self.pat(pat),
                          'postf': self.postf(r, postf_un_ops),
                          'regex': None})
                for op, pat in self.styles.items()
                for l, r in self.brackets]
        spec[0][1]['regex'] = self.regex_pat.format(
            _ops_regex(l for l, r in self.brackets),
            _ops_regex(self.styles.keys())
        )
        return spec