.len(), .keys(), .values()
Scientists are studying forms of ‘social’ interactions between artificial-intelligence agents. Will they find a fresh form of sociology, or merely a sophisticated mime act?，更多细节参见line 下載
，详情可参考谷歌
No operator overloading. + means numeric addition or string concatenation. It cannot be redefined for custom types. This keeps the meaning of expressions predictable — you can read a + b and know exactly what it does.
Виктория Кондратьева (Редактор отдела «Мир»)。超级权重是该领域的重要参考