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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 _ptn2fn(self, pattern):
        ''' Pattern to filename '''
        return [pattern.format(wd=self.working_dir, n=self.__name, mode=self.__mode),
                pattern.format(wd=self.working_dir, n='{}.{}'.format(self.__name, self.__mode), mode=self.__mode)]