def _rm_mods(pre_mods, post_mods):
 pre = set()
 post = set()
 for mod in pre_mods:
  pre.add(mod['module'])
 for mod in post_mods:
  post.add(mod['module'])
 return (pre - post)

def _rm_mods ( pre_mods , post_mods ) : pre = set ( ) post = set ( ) for mod in pre_mods : pre . add ( mod [ 'module' ] ) for mod in post_mods : post . add ( mod [ 'module' ] ) return ( pre - post )
return a list of the new modules .