web.memoize，貌似是缓存函数返回值的

文档中的实例

 

 |      >>> calls = 0
 |      >>> def howmanytimeshaveibeencalled():
 |      ...     global calls
 |      ...     calls += 1
 |      ...     return calls
 |      >>> fastcalls = memoize(howmanytimeshaveibeencalled)
 |      >>> howmanytimeshaveibeencalled()
 |      1
 |      >>> howmanytimeshaveibeencalled()
 |      2
 |      >>> fastcalls()
 |      3
 |      >>> fastcalls()
 |      3