On Sun, May 13, 2018 at 5:17 PM, Ethan Furman <et...@stoneleaf.us> wrote: > On 05/12/2018 11:41 PM, Tim Peters wrote: >> >> [Tim, suggests changes to the Reference Manual's 4.2.1] >>> >>> """ >>> An assignment expression binds the target, except in a function F >>> synthesized to implement a list comprehension or generator expression >>> (see XXX). In the latter case, if the target is not in F's >>> environment (see section 4.2.2) , the target is bound in the block >>> containing F. >>> """ >> >> >> Let me try that again ;-) The notion of "environment" includes the >> global scope, but that's not really wanted here. "Environment" has >> more of a runtime flavor anyway. And since nobody will tell me >> anything about class scope, I read the docs myself ;-) >> >> And that's a problem, I think! If a comprehension C is in class scope >> S, apparently the class locals are _not_ in C's environment. Since C >> doesn't even have read access to S's locals, it seems to me bizarre >> that ":=" could _create_ a local in S. > > > Python 3.7.0b3+ (heads/bpo-33217-dirty:28c1790, Apr 5 2018, 13:10:10) > [GCC 4.8.2] on linux > Type "help", "copyright", "credits" or "license" for more information. > --> class C: > ... huh = 7 > ... hah = [i for i in range(huh)] > ... > --> C.hah > [0, 1, 2, 3, 4, 5, 6] > > Same results clear back to 3.3 (the oldest version of 3 I have). Are the > docs wrong?
>>> class C: ... huh = 7 ... hah = [i for _ in [0] for i in range(huh)] ... Traceback (most recent call last): File "<stdin>", line 1, in <module> File "<stdin>", line 3, in C File "<stdin>", line 3, in <listcomp> NameError: name 'huh' is not defined The outermost iterable is a special case. Otherwise, you can't reference anything. ChrisA _______________________________________________ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/
