Python list.index throws exception when index not found

Question

Why does list.index throw an exception, instead of using an arbitrary value (for example, -1)? What\'s the idea behind this?

To me it looks cleaner to d

Answer 1

To add to Devin's response: This is an old debate between special return values versus exceptions. Many programming gurus prefer an exception because on an exception, I get to see the whole stacktrace and immediate infer what is wrong.