Antoine Pitrou wrote:
Why not a dedicated exception (e.g. GeneratorReturn) instead? Two advantages to doing so: * people mistakingly doing a "for" loop over such a generator would be reminded that they are missing something (the return value)
You don't get an warning that you are "missing something" if you ignore the return value from an ordinary function call, so I don't find this argument very convincing.
* you could take advantage of existing iterator-consuming features (e.g. "yield from map(str, innergenerator())"), since they would just forward the exception instead of silencing it
You also don't get ordinary return values of functions that you call forwarded to your caller, and I don't see how it would be any more useful to do so here. There is one possible reason it might be useful, and that's if you want to catch a StopIteration that may or may not have a value attached, i.e. try: # some iteration thing except GeneratorReturn, e: result = e.args[0] except StopIteration: result = None However, that would be better addressed by enhancing StopIteration with a 'value' attribute that is None if it wasn't given an argument. -- Greg