On 7/7/07, Phillip J. Eby <[EMAIL PROTECTED]> wrote: > At 12:32 AM 7/7/2007 +0200, Guido van Rossum wrote: > >On 7/6/07, Phillip J. Eby <[EMAIL PROTECTED]> wrote: > > > At 05:00 PM 7/6/2007 +0200, Georg Brandl wrote: > > > >Collin Winter schrieb: > > > > > While experimenting with porting setuptools to py3k (as of r56155), I > > > > > ran into this situation: > > > > > > > > > > class C: > > > > > a = (4, 5) > > > > > b = [c for c in range(2) if a] > > > > > > > > > > results in a "NameError: global name 'a' is not defined" error, while > > > > > > > > > > class C: > > > > > a = (4, 5) > > > > > b = [c for c in a] > > > > > > > > > > works fine. > > > > > > This looks like a bug to me. A list comprehension's local scope > > > should be the locals of the enclosing code, even if its loop indexes > > > aren't exposed to that scope. > > > >It's because the class scope is not made available to the methods. > > The examples are in the class body, not in methods. The code is > statically initializing the class contents, so using C.a isn't possible.
Understood, but a generator expression (and hence in 3.0 also a list comprehension) is treated the same as a method body. > I suppose it can be worked around by moving the static initialization > code outside the class body; it's just not obvious why it happens. > > Collin, where did you find this code in setuptools, btw? I've been > looking around at other packages of mine where static class > initialization uses data structures like this, and I haven't found > any place where anything but the "in" clause of a comprehension > depends on class-scope variables. So, if setuptools is the only one > of my libraries that does this, I'd have to agree with Guido that it > is indeed quite rare. :) > > If I had to hazard a guess, I'd guess that it's in one of the > setuptools command classes that subclasses a distutils command, and > proceeds to muck around with the original options in some fashion. I > just don't want to check all of them if you know which one it is. :) > > -- --Guido van Rossum (home page: http://www.python.org/~guido/) _______________________________________________ Python-3000 mailing list Python-3000@python.org http://mail.python.org/mailman/listinfo/python-3000 Unsubscribe: http://mail.python.org/mailman/options/python-3000/archive%40mail-archive.com
