New submission from Erick Tryzelaar <[EMAIL PROTECTED]>: This may be a known consequence of python 3.0, but I couldn't find any reference to it, nor a test case that covers it. Here's a valid use of yield in 2.5.1:
>>> def foo(): ... x=[(yield x) for x in 1,2,3] ... yield 5 ... yield x >>> x=foo() >>> x.next() 1 >>> x.send(6) 2 >>> x.send(7) 3 >>> x.send(8) 5 >>> x.send(9) [6, 7, 8] >>> x.send(10) Traceback (most recent call last): File "<stdin>", line 1, in <module> StopIteration But in python 3.0, this code results in: >>> def foo(): ... x=[(yield x) for x in (1,2,3)] ... yield 5 ... yield x >>> x=foo() >>> next(x) 5 >>> x.send(6) <generator object <listcomp> at 0x3678f0> >>> x.send(7) Traceback (most recent call last): File "<stdin>", line 1, in <module> StopIteration Looking further, it seems that this is a comprehension: >>> def foo(): [(yield 5)] >>> type(foo()) <class 'generator'> Whereas this is not: >>> def foo(): [(yield 5) for x in range(3)] >>> type(foo()) <class 'NoneType'> Is this expected behavior? ---------- components: Interpreter Core messages: 69168 nosy: erickt severity: normal status: open title: yield in list comprehensions possibly broken in 3.0 versions: Python 3.0 _______________________________________ Python tracker <[EMAIL PROTECTED]> <http://bugs.python.org/issue3267> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
