Ever since I've been using exceptions, uncertainty has always been there: when are we better off with return codes? when is it smart to catch the exceptions? when should they better be left untouched and propagate higher? Create a separate exception class, or just pass an argument to the constructor?
During the recent few years, I've been gathering some best practices I learned from my peers and by experience, which I'll dump here to a short series of posts. I hope it'll help to provoke some discussion on this rather important design matter. As it's a highly debatable matter, discussions are more effective than trying to declare the ultimate truth of proper usage of exceptions.
Most of my experience in this area is related to Python, but I believe the same discussion usually applies to all dynamic languages, and possibly to languages that use throw rather than raise.
Enough disclaimers, let's get started. An easy one for starters: