Re: [Python-Dev] Is it intentional that sys.__debug__ = 1 is illegal in Python 2.7?
On Aug 01, 2010, at 09:56 PM, Benjamin Peterson wrote: 2010/7/30 Barry Warsaw ba...@python.org: It looks like Benjamin's change in r67171 was the relevant diff. The reason behind this was to make __debug__ assignment consistent with that of other reserved names. For example, x.None = 3 raised and thus, so should x.__debug__ = 3. BTW, thanks to Georg for closing the documentation issue. -Barry signature.asc Description: PGP signature ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Is it intentional that sys.__debug__ = 1 is illegal in Python 2.7?
2010/7/30 Barry Warsaw ba...@python.org: It looks like Benjamin's change in r67171 was the relevant diff. The reason behind this was to make __debug__ assignment consistent with that of other reserved names. For example, x.None = 3 raised and thus, so should x.__debug__ = 3. -- Regards, Benjamin ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Is it intentional that sys.__debug__ = 1 is illegal in Python 2.7?
On Jul 31, 2010, at 08:32 AM, Steven D'Aprano wrote: On Sat, 31 Jul 2010 07:44:42 am Guido van Rossum wrote: On Fri, Jul 30, 2010 at 1:53 PM, Barry Warsaw ba...@python.org wrote: On Jul 30, 2010, at 01:42 PM, Guido van Rossum wrote: Well it is a reserved name so those packages that were setting it should have known that they were using undefined behavior that could change at any time. Shouldn't it be described here then? http://docs.python.org/reference/lexical_analysis.html#identifiers No, since it is covered here: http://docs.python.org/reference/lexical_analysis.html#reserved-class es-of-identifiers I have a small concern about the wording of that, specifically this: System-defined names. These names are defined by the interpreter and its implementation (including the standard library); applications SHOULD NOT EXPECT TO DEFINE additional names using this convention. The set of names of this class defined by Python may be extended in future versions. [emphasis added] This implies to me that at some time in the future, Python may make it illegal to assign to any __*__ name apart from those in a list of approved methods. Is that the intention? I have always understood that if you create your own __*__ names, you risk clashing with a special method, but otherwise it is allowed, if disapproved off. I would not like to see it become forbidden. I'm with Steven on this one. I've always understood the rules on double-underscore names to mean that Python reserves the use of those names for its own purposes, and is free to break your code if you define your own. That's very different than saying it's forbidden to use double-underscore names for your own purposes or assign to them, which is I think what's going on with the sys.__debug__ example. If that's the rule, I'd want to make this section of the documentation much stronger about the prohibitions. I've just never considered Python's rule here to be that strong. -Barry signature.asc Description: PGP signature ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Is it intentional that sys.__debug__ = 1 is illegal in Python 2.7?
Barry Warsaw wrote: I've always understood the rules on double-underscore names to mean that Python reserves the use of those names for its own purposes, and is free to break your code if you define your own. That's very different than saying it's forbidden to use double-underscore names for your own purposes or assign to them, which is I think what's going on with the sys.__debug__ example. I don't see that there's any difference. Once upon a time, __debug__ wasn't special, and someone decided to use it for their own purposes. Then Guido decided to make it special, and broke their code, which is within the rules as you just stated them. The rule doesn't say anything about what *kinds* of breakage are allowed, so anything goes, including making it impossible to assign to the name any more. -- Greg ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Is it intentional that sys.__debug__ = 1 is illegal in Python 2.7?
On Fri, Jul 30, 2010 at 1:26 PM, Barry Warsaw ba...@python.org wrote: In working on making Python 2.7 available in Debian and Ubuntu, we ran into two packages that fail to byte compile against Python 2.7, where they are fine in Python 2.6. The Debian bug tracker issues are: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=590821 http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=590822 Specifically, what fails now is assignment to the __debug__ attribute of a module, e.g. sys -- *not* builtin __debug__. % python2.6 Python 2.6.5 (r265:79063, Apr 16 2010, 13:57:41) [GCC 4.4.3] on linux2 Type help, copyright, credits or license for more information. __debug__ = 1 File stdin, line 1 SyntaxError: can not assign to __debug__ import sys sys.__debug__ = 1 % python2.7 Python 2.7.0+ (release27-maint:83294, Jul 30 2010, 15:49:51) [GCC 4.4.3] on linux2 Type help, copyright, credits or license for more information. __debug__ = 1 File stdin, line 1 SyntaxError: cannot assign to __debug__ import sys sys.__debug__ = 1 File stdin, line 1 SyntaxError: cannot assign to __debug__ I think it's actually somewhat questionable that this is now illegal. It certainly breaks at least two packages. More disturbing though is that I cannot find mention of this change in Misc/NEWS or in the tracker, so I don't actually know if this was intentional or not. Well it is a reserved name so those packages that were setting it should have known that they were using undefined behavior that could change at any time. It looks like Benjamin's change in r67171 was the relevant diff. Thoughts? Either way I will file a bug. IOW, if this change should *not* have been made, I think it should be reverted for Python 2.7.1 and I can patch our version of Python in the meantime. If this change is intentional, I'll file a bug against (or just fix) Misc/NEWS and the What's New. -- --Guido van Rossum (python.org/~guido) ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Is it intentional that sys.__debug__ = 1 is illegal in Python 2.7?
On Jul 30, 2010, at 01:42 PM, Guido van Rossum wrote: Well it is a reserved name so those packages that were setting it should have known that they were using undefined behavior that could change at any time. Shouldn't it be described here then? http://docs.python.org/reference/lexical_analysis.html#identifiers -Barry signature.asc Description: PGP signature ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Is it intentional that sys.__debug__ = 1 is illegal in Python 2.7?
On 30/07/2010 21:53, Barry Warsaw wrote: On Jul 30, 2010, at 01:42 PM, Guido van Rossum wrote: Well it is a reserved name so those packages that were setting it should have known that they were using undefined behavior that could change at any time. Shouldn't it be described here then? http://docs.python.org/reference/lexical_analysis.html#identifiers And raise a DeprecationWarning one release before becoming invalid syntax? Michael -Barry ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/fuzzyman%40voidspace.org.uk -- http://www.ironpythoninaction.com/ http://www.voidspace.org.uk/blog READ CAREFULLY. By accepting and reading this email you agree, on behalf of your employer, to release me from all obligations and waivers arising from any and all NON-NEGOTIATED agreements, licenses, terms-of-service, shrinkwrap, clickwrap, browsewrap, confidentiality, non-disclosure, non-compete and acceptable use policies (BOGUS AGREEMENTS) that I have entered into with your employer, its partners, licensors, agents and assigns, in perpetuity, without prejudice to my ongoing rights and privileges. You further represent that you have the authority to release me from any BOGUS AGREEMENTS on behalf of your employer. ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Is it intentional that sys.__debug__ = 1 is illegal in Python 2.7?
2010/7/30 Barry Warsaw ba...@python.org: On Jul 30, 2010, at 01:42 PM, Guido van Rossum wrote: Well it is a reserved name so those packages that were setting it should have known that they were using undefined behavior that could change at any time. Shouldn't it be described here then? http://docs.python.org/reference/lexical_analysis.html#identifiers Doesn't the section http://docs.python.org/reference/lexical_analysis.html#reserved-classes-of-identifiers make this clear enough ? -Barry ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/ggpolo%40gmail.com -- -- Guilherme H. Polo Goncalves ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Is it intentional that sys.__debug__ = 1 is illegal in Python 2.7?
On Fri, Jul 30, 2010 at 1:53 PM, Barry Warsaw ba...@python.org wrote: On Jul 30, 2010, at 01:42 PM, Guido van Rossum wrote: Well it is a reserved name so those packages that were setting it should have known that they were using undefined behavior that could change at any time. Shouldn't it be described here then? http://docs.python.org/reference/lexical_analysis.html#identifiers No, since it is covered here: http://docs.python.org/reference/lexical_analysis.html#reserved-classes-of-identifiers -- --Guido van Rossum (python.org/~guido) ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Is it intentional that sys.__debug__ = 1 is illegal in Python 2.7?
On Sat, 31 Jul 2010 07:44:42 am Guido van Rossum wrote: On Fri, Jul 30, 2010 at 1:53 PM, Barry Warsaw ba...@python.org wrote: On Jul 30, 2010, at 01:42 PM, Guido van Rossum wrote: Well it is a reserved name so those packages that were setting it should have known that they were using undefined behavior that could change at any time. Shouldn't it be described here then? http://docs.python.org/reference/lexical_analysis.html#identifiers No, since it is covered here: http://docs.python.org/reference/lexical_analysis.html#reserved-class es-of-identifiers I have a small concern about the wording of that, specifically this: System-defined names. These names are defined by the interpreter and its implementation (including the standard library); applications SHOULD NOT EXPECT TO DEFINE additional names using this convention. The set of names of this class defined by Python may be extended in future versions. [emphasis added] This implies to me that at some time in the future, Python may make it illegal to assign to any __*__ name apart from those in a list of approved methods. Is that the intention? I have always understood that if you create your own __*__ names, you risk clashing with a special method, but otherwise it is allowed, if disapproved off. I would not like to see it become forbidden. -- Steven D'Aprano ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
