I did not want to make a list, I wanted to create a tuple thank you for catching it. I want parens not square brackets there.

为什么这里有错误了，我并不想要创建,一个列表，我想创建一个元组，谢谢你,发现了这个错误。

麻省理工公开课 - 计算机科学及编程导论课程节选

So if we want to put that in chemical terms, we want to make sure we put these in brackets here, and remember, this is the resonance arrow, it's not a reaction arrow, it's a resonance arrow, so make sure you mark it up correctly like that.

那么如果我们把它类比到化学中来，我们要确保它们都放在括号里，而且要记住，这是一个表示共振态的箭头，而不是表示化学反应的，它是一个表示共振态的箭头，因此请务必像这样正确地标记它。

麻省理工公开课 - 化学原理课程节选