I just want to remind you, if I wanted to, for example, type in an expression like that, notice the syntactical form, it's an expression, a number, followed by an operand, followed by another expression.

我想要提醒下大家，如果你想要，例如，输入一个这样的表达式，注意语法形式，这是个表达式，一个数字，后面是一个运算对象，后面是另外一个表达式。

麻省理工公开课 - 计算机科学及编程导论课程节选

Before I type in that expression, I get an error, right?

在我输入表达式之前，出现一个错误，对吧？

麻省理工公开课 - 计算机科学及编程导论课程节选

The answer was, find a mathematical expression depending on the number of inputs.

很不错，答案是，找到一个通过输入数字,计算出来的数字表达式。

麻省理工公开课 - 计算机科学及编程导论课程节选

Which is, and we're going to do some examples of this, initially we just typed in expressions Python into the interpreter; that is,directly into Python And as I suggested last time, the interpreter is actually a program inside of the machine that is basically following the rules we're describing here to deduce the value and print it up.

也就是，我们将会对这一点讲解一些例子，一开始我们只是简单的把表达式输入,到解释器里面去，也就是直接传给,我上次跟大家讲过，解释器实际上是,机器内置的,按照我们描述的规则,来推算出结果值并把值显示出来的一个东西。

麻省理工公开课 - 计算机科学及编程导论课程节选

When we're just interacting with idol, with the interactive editor or sorry, interactive environment if you like, that's what you expect. What's happening is that we're typing in something, an expression it doesn't know how to deal. It's raising the exception, but is this simply bubbling up at the top level saying you've got a problem.

就发生了其中之一是吧，当你在交互数据处理或者是在交互编辑器，抱歉，任何你喜欢的交互式环境中，你可能会遇到这些，如果你在输入什么内容,譬如一个它不知道怎么处理的表达式,它就会报一个异常,但这是否是简单的,把你遇到的问题冒到最顶层呢？

麻省理工公开课 - 计算机科学及编程导论课程节选

So. Starting with the shell, I can type in expressions.

好，从sell开始，我可以输入一些表达式。

麻省理工公开课 - 计算机科学及编程导论课程节选