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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 clean(self):
 """ Remove intermediate files created. """

        #TODO: add cleaning of mask files, *if* created ...
        for f in self.catalog_names:
            if 'match' in f:
                if os.path.exists(self.catalog_names[f]):
                    log.info('Deleting intermediate match file: %s'%
                                self.catalog_names[f])
                    os.remove(self.catalog_names[f])
            else:
                for extn in f:
                    if os.path.exists(extn):
                        log.info('Deleting intermediate catalog: %d'%extn)
                        os.remove(extn)