Bugs item #992389, was opened at 2004-07-16 17:09 Message generated for change (Comment added) made by loewis You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=105470&aid=992389&group_id=5470
Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Python Interpreter Core Group: Python 2.3 Status: Open Resolution: None >Priority: 5 Submitted By: Jim Fulton (dcjim) Assigned to: Nobody/Anonymous (nobody) Summary: attribute error after non-from import Initial Comment: This bug applied to 2.3 and 2.4. It probably applies to earlier versions, but who cares? :) Under some circumstances, code like: import eek.foo.baz y = eek.foo.baz.y fails with an attribute error for "foo" if foo is still being imported. I've attached a zip file of a demo package "eek" that demonstrates the problem. If you unzip the package and: import eek.foo you'll get the attribute error described above. I think the problem is that eek's foo attribute isn't set until the import of foo is finished. This is too late. ---------------------------------------------------------------------- >Comment By: Martin v. Löwis (loewis) Date: 2006-07-03 14:38 Message: Logged In: YES user_id=21627 Lowering the priority, as this apparently is not a high-priority issue. ---------------------------------------------------------------------- Comment By: Tim Peters (tim_one) Date: 2004-11-16 03:03 Message: Logged In: YES user_id=31435 Nick, the semantics of circular imports aren't clear even if no packages are involved. Note that the Reference manual is silent about such cases. In effect, it's defined by the implementation, and some people think they know how that works -- although nobody has credibly claimed to fully understand the implementation consequences since Gordon McMillan vanished <0.5 wink>. While I expect this bug report to sit here for years (it's hard to imagine anyone caring enough to devote the time needed to untangle this subsystem), I'll note in passing that this case "works" if bar.py uses relative import instead; i.e., if it begins with import baz y = baz.y instead of with import eek.foo.baz y = eek.foo.baz.y Then it stops referencing attributes that don't exist before the whole chain of imports completes. ---------------------------------------------------------------------- Comment By: Nick Coghlan (ncoghlan) Date: 2004-11-15 12:08 Message: Logged In: YES user_id=1038590 If the semantics aren't clear, then isn't that a bug in itself? If the behaviour of Jim's code is officially undefined, then the docs need to say so. A simple rule would seem to be "a package should not try to import itself or any subpackages with an absolute import in its __init__.py file". Given the nature of __all__ and __path__ for packages, I can't see a way to safely set eek's foo attribute before foo's __init__.py has been processed. ---------------------------------------------------------------------- Comment By: Jeremy Hylton (jhylton) Date: 2004-11-07 16:30 Message: Logged In: YES user_id=31392 Are the semantics of import clear enough to confirm that this is a bug? Specifically, this seems to revolve around circular imports and code in __init__. I agree that this behavior is confusing, but I don't know if that has more to do with the nature of circular imports than any bug. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=105470&aid=992389&group_id=5470 _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
