New submission from Greg Kochanski <g...@kochanski.org>: When you have a generator as an argument to zip(), code after the last yield statement may not get executed. The problem is that zip() stops after it gets _one_ exception, i.e. when just one of the generators has finished.
As a result, if there were any important clean-up code at the end of a generator, it will not be executed. Caches may not get flushed, et cetera. At the least, this is a documentation bug that needs to be pointed out in both zip() and the definition of a generator(). More realistically, it is a severe wart on the language, because it violates the programmer's reasonable expectation that a generator executes until it falls off the end of the function. It means that a generator becomes conceptually nasty: you cannot predict what it will do based just on an inspection of the code and the code it calls. Likely, the same behavior happens in itertools, too. ---------- components: None files: bug312.py messages: 128842 nosy: gpk-kochanski priority: normal severity: normal status: open title: Tails of generator get lost under zip() type: behavior versions: Python 2.6 Added file: http://bugs.python.org/file20794/bug312.py _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue11248> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
