Thinking Step 1: 分析题目条件。“你们都要”意味着 A AND B AND C = True。
Web streams has no synchronous path. Even if your source has data ready and your transform is a pure function, you still pay for promise creation and microtask scheduling on every operation. Promises are fantastic for cases in which waiting is actually necessary, but they aren't always necessary. The new API lets you stay in sync-land when that's what you need.
，更多细节参见同城约会
Rock & Roll Hall of Fame picks Outkast but not Oasis
So Nasa opted for the next scheduled flight: a SpaceX capsule that arrived at the ISS in late September.
from urllib.parse import urljoin, urlparse