code: def get_subdir(index):
      
      try:
          return index['subdir']
      except KeyError:
          arch = index.get('arch')
          if arch is None:
              return 'noarch'
          intel_map = {'x86': '32', 'x86_64': '64'}
          return '%s-%s' % (index.get('platform'), intel_map.get(arch, arch))
docs: Return the sub-directory given the index dictionary.  The return
      value is obtained in the following order:
  
      1. when the 'subdir' key exists, it's value is returned
      2. if the 'arch' is None, or does not exist, 'noarch' is returned
      3. otherwise, the return value is constructed from the 'platform' key
         and the 'arch' key (where 'x86' is replaced by '32',
         and 'x86_64' by '64')