tuplen.元组；数组；重数tuple identifier元组标识符tuple clustering元组群集tuple space search元组空间搜索tuple structured data元组结构数据tuple random placement元组随机替换tuple calculus language元组演算语言tuple-based rationale基于元组的理论tuple relational calculus元组关系演算tuple-oriented argument面向元组的变元Tuple as a class attribute.元组作为类属性。

1. Returns the number of distinct, nonempty tuples in a set.
   返回集中非重复的非空元组的数目。
2. It is also possible to create tuples which contain mutable objects, such as lists.
   也可以通过包含可变对象来创建元组，例如链表。