On Sat, Feb 22, 2020 at 10:32 AM Greg Ewing <greg.ew...@canterbury.ac.nz> wrote: > > On 22/02/20 11:45 am, Andrew Barnert via Python-ideas wrote: > > there’s no reason you can’t write `[(yield None) for _ in range(3)]` to > > gather the first three values sent into your generator > > Currently this doesn't quite do what you might expect. > It doesn't make the enclosing function into a generator, > it make the list comprehension itself a generator: > > >>> def f(): > ... return [(yield x) for x in range(10)] > ... > >>> g = f() > >>> g > <generator object f.<locals>.<listcomp> at 0x6b396c> > >>> > > I don't think this behaviour is deliberate; it seems to > be a consequence of deciding to compile the body of the > comprehension as a nested function. >
Depends what you mean by "currently". Python 3.7.0a4+ (heads/master:95e4d58913, Jan 27 2018, 06:21:05) [GCC 6.3.0 20170516] on linux >>> def f(): ... return [(yield x) for x in range(10)] ... >>> Python 3.8.2rc2+ (heads/3.8:a207512121, Feb 21 2020, 21:49:46) [GCC 6.3.0 20170516] on linux >>> def f(): ... return [(yield x) for x in range(10)] ... File "<stdin>", line 2 SyntaxError: 'yield' inside list comprehension https://docs.python.org/3/whatsnew/3.8.html#changes-in-python-behavior ChrisA _______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-le...@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/XGAZFCMKUD2VCECYVBPKYDHMUUUBM3O3/ Code of Conduct: http://python.org/psf/codeofconduct/
