什么时候在Python中引发KeyboardInterrupt？ [英] When is KeyboardInterrupt raised in Python?

问题描述

所有文档告诉我们的是

在用户按下中断键时引发（通常 Control- C 或 Delete ）。在执行过程中，会定期检查中断。

Raised when the user hits the interrupt key (normally Control-C or Delete). During execution, a check for interrupts is made regularly.

但是从代码的角度来看，什么时候可以看到这个？ ？是否在语句执行期间发生？仅在语句之间？

But from the point of the code, when can I see this exception? Does it occur during statement execution? Only between statements? Can it happen in the middle of an expression?

例如：

file_ = open('foo')
# <-- can a KeyboardInterrupt be raised here, after the successful
# completion of open but prior to the try? -->
try:
    # try some things with file_
finally:
    # cleanup

在适当的 KeyboardInterrupt 期间此代码会泄漏吗？还是在执行某些语句或表达式期间引发它？

Will this code leak during a well-timed KeyboardInterrupt? Or is it raised during the execution of some statements or expressions?

推荐答案

根据不相关的 PEP 343 ：

即使您编写无错误的代码，KeyboardInterrupt异常仍可能导致它在任何两个虚拟机操作码之间退出。

Even if you write bug-free code, a KeyboardInterrupt exception can still cause it to exit between any two virtual machine opcodes.

因此，它基本上可以发生在任何地方。它确实可以在单个表达式的求值过程中发生。 （这并不奇怪，因为表达式可以包含函数调用，并且函数调用内部几乎可以发生任何事情。）

So it can occur essentially anywhere. It can indeed occur during evaluation of a single expression. (This shouldn't be surprising, since an expression can include function calls, and pretty much anything can happen inside a function call.)

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