code: def _get_platform_patterns(spec, package, src_dir):
          
          raw_patterns = itertools.chain(
              spec.get('', []),
              spec.get(package, []),
          )
          return (
              # Each pattern has to be converted to a platform-specific path
              os.path.join(src_dir, convert_path(pattern))
              for pattern in raw_patterns
          )
docs: yield platform-specific path patterns (suitable for glob
          or fn_match) from a glob-based spec (such as
          self.package_data or self.exclude_package_data)
          matching package in src_dir.