On Thu, Jan 8, 2015 at 5:11 AM, Chris Angelico <ros...@gmail.com> wrote: > As yield is an expression, it's legal in a lambda function, which then > means you have a generator function. But it's not quite the same as > the equivalent function made with def: > > $ python3 > Python 3.5.0a0 (default:1c51f1650c42+, Dec 29 2014, 02:29:06) > [GCC 4.7.2] on linux > Type "help", "copyright", "credits" or "license" for more information. >>>> f=lambda: (yield 5) >>>> x=f() >>>> next(x) > 5 >>>> x.send(123) > Traceback (most recent call last): > File "<stdin>", line 1, in <module> > StopIteration >>>> def f(): return (yield 5) > ... >>>> x=f() >>>> next(x) > 5 >>>> x.send(123) > Traceback (most recent call last): > File "<stdin>", line 1, in <module> > StopIteration: 123 > > > Is this a bug? I very much doubt any sane code will ever run into > this; I discovered this purely by chance, after noting that > Python/compile.c had code to create a generator. The same thing > happens with Python 3.4.2 on Debian Jessie, so this isn't a bug I've > introduced in my local fiddling around.
I don't see anything in PEP 380 suggesting that it shouldn't apply to lambda functions. >>> def f(g): ... v = (yield from g) ... yield v ... >>> g = lambda: (yield 42) or (yield 43) or (yield 44) or "hello world" >>> list(f(g())) [42, 43, 44, None] Seems like a bug to me. -- https://mail.python.org/mailman/listinfo/python-list
