code: def exclude_data_files(self, package, src_dir, files):
          
          files = list(files)
          patterns = self._get_platform_patterns(
              self.exclude_package_data,
              package,
              src_dir,
          )
          match_groups = (
              fnmatch.filter(files, pattern)
              for pattern in patterns
          )
          # flatten the groups of matches into an iterable of matches
          matches = itertools.chain.from_iterable(match_groups)
          bad = set(matches)
          keepers = (
              fn
              for fn in files
              if fn not in bad
          )
          # ditch dupes
          return list(_unique_everseen(keepers))
docs: Filter filenames for package's data files in 'src_dir