code: def lookup(dic, key, *keys):
      
      if keys:
          return lookup(dic.get(key, {}), keys[0], *keys[1:])
      return dic.get(key)
docs: A generic dictionary access helper.
  
      This helps simplify code that uses heavily nested dictionaries. It will
      return None if any of the keys in *keys do not exist.
  
      ::
  
          >>> lookup({'this': {'is': 'nested'}}, 'this', 'is')
          nested
  
          >>> lookup({}, 'this', 'is')
          None