[issue11205] Evaluation order of dictionary display is different from reference manual.

Nick Coghlan added the comment: I'm unlikely to ever get to this (especially as 3.5 is now in security-fix only mode), so closing it again. -- nosy: +freakboy, freakboy3742 resolution: -> fixed stage: needs patch -> resolved status: open -> closed

[issue11205] Evaluation order of dictionary display is different from reference manual.

Nick Coghlan added the comment: Temporarily reopening this as a docs bug - I think it's worth mentioning in the "Porting to Python 3.5" section of the What's New docs and as a "version changed" note in the dis module docs, as even though it's obscure, anyone that was inadvertently relying on

[issue11205] Evaluation order of dictionary display is different from reference manual.

Steve Dougherty added the comment: Anyone care to review issue11205-v3.patch ? -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue11205 ___ ___

[issue11205] Evaluation order of dictionary display is different from reference manual.

Terry J. Reedy added the comment: I downloaded and tried to apply to 3.5 (then default) as it was last Saturday, before the .b1 cutoff. Only ceval.py and test_compile.py patches worked. Everything else failed. You need to update your repository (3.5 is now a branch and default is 3.6) and

[issue11205] Evaluation order of dictionary display is different from reference manual.

Roundup Robot added the comment: New changeset 6f05f83c7010 by Benjamin Peterson in branch '3.5': in dict displays, evaluate the key before the value (closes #11205) https://hg.python.org/cpython/rev/6f05f83c7010 New changeset ba9e4df5368c by Benjamin Peterson in branch 'default': merge 3.5

[issue11205] Evaluation order of dictionary display is different from reference manual.

Steve Dougherty added the comment: I've added a change to the bytecode magic number as well. I don't see a magic tag anymore, either in the code or for recent versions. There are autogenerated changes to Python/importlibs.h. Is my understanding correct that these are not to be committed?

[issue11205] Evaluation order of dictionary display is different from reference manual.

Eric Snow added the comment: Changes to importlib.h should always be committed. It is the frozen importlib._bootstrap module, which is the implementation of the import system used by the interpreter. So failure to commit changes to importlib.h means your changes to importlib._bootstrap will

[issue11205] Evaluation order of dictionary display is different from reference manual.

Steve Dougherty added the comment: I've added the importlib.h changes and changed the name of the test to be more descriptive. -- Added file: http://bugs.python.org/file39228/issue11205-v3.patch ___ Python tracker rep...@bugs.python.org

[issue11205] Evaluation order of dictionary display is different from reference manual.

Steve Dougherty added the comment: I've added a patch to change the order of evaluation and of STORE_MAP's arguments. It includes a test incorporating the review on the previous version. I noticed I had to remove existing .pyc files to avoid TypeErrors about values being unhashable. I take it

[issue11205] Evaluation order of dictionary display is different from reference manual.

Nick Coghlan added the comment: The pyc issue suggests the magic number embedded in pyc files to indicate bytecode compatibility needs to be incremented. If I recall correctly, that lives in Lib/importlib/_bootstrap.py these days. -- ___ Python

[issue11205] Evaluation order of dictionary display is different from reference manual.

Changes by Raymond Hettinger raymond.hettin...@gmail.com: -- priority: low - high ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue11205 ___ ___

[issue11205] Evaluation order of dictionary display is different from reference manual.

Steve Dougherty added the comment: Any word on either changing the documentation to match the behaviour or fixing this as a bug? -- nosy: +sdougherty ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue11205

[issue11205] Evaluation order of dictionary display is different from reference manual.

Guido van Rossum added the comment: This needs a code patch. But it can only be fixed for 3.5. On Apr 7, 2015 11:21 AM, Steve Dougherty rep...@bugs.python.org wrote: Steve Dougherty added the comment: Any word on either changing the documentation to match the behaviour or fixing this as a

[issue11205] Evaluation order of dictionary display is different from reference manual.

Changes by Terry J. Reedy tjre...@udel.edu: -- versions: -Python 3.2 ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue11205 ___ ___ Python-bugs-list

[issue11205] Evaluation order of dictionary display is different from reference manual.

Ned Batchelder added the comment: Since this is documented in the Python Language Reference, it doesn't make much sense to have it describe one way for 3.3 and another for 3.4, does it? By definition, doesn't that make this an implementation dependency? We should update the docs to say that

[issue11205] Evaluation order of dictionary display is different from reference manual.

Terry J. Reedy added the comment: I strongly agree with Guido that we should fix the code. To me, defined left-to-right evaluation of sub-expressions within an expression is a feature. C's 'implementation defined' is a nuisance. I do not think we should temporarily change the doc. In other

[issue11205] Evaluation order of dictionary display is different from reference manual.

Guido van Rossum added the comment: I am sticking with my opinion from before: the code should be fixed. It doesn't look like assignment to me. I am fine with making this a feature only fixed in 3.4. (You can even fix the docs in 3.3 as long as you fix them back for 3.4.) Minor note for

[issue11205] Evaluation order of dictionary display is different from reference manual.

Ezio Melotti added the comment: I came across the same problem in #16777. IMHO the current behavior is better, and the documentation should be fixed instead, for the following reasons: 1) it's consistent with assignments, where the RHS is evaluated before the LHS (see also msg128500). This

[issue11205] Evaluation order of dictionary display is different from reference manual.

Changes by Nick Coghlan ncogh...@gmail.com: -- nosy: +ncoghlan priority: high - low versions: +Python 3.4 ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue11205 ___

[issue11205] Evaluation order of dictionary display is different from reference manual.

Terry J. Reedy added the comment: Today in pydev thread chained assignment weirdity Guido said http://permalink.gmane.org/gmane.comp.python.devel/135746 I agree that we should be *very* conservative in changing the meaning of existing opcodes (adding new one is a different story). ... Hm. I

[issue11205] Evaluation order of dictionary display is different from reference manual.

Changes by Antoine Pitrou pit...@free.fr: -- nosy: +benjamin.peterson ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue11205 ___ ___ Python-bugs-list

[issue11205] Evaluation order of dictionary display is different from reference manual.

Changes by Terry J. Reedy tjre...@udel.edu: -- components: +Interpreter Core -None ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue11205 ___ ___

[issue11205] Evaluation order of dictionary display is different from reference manual.

Changes by Sandro Tosi sandro.t...@gmail.com: -- nosy: +sandro.tosi ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue11205 ___ ___ Python-bugs-list

[issue11205] Evaluation order of dictionary display is different from reference manual.

Terry J. Reedy tjre...@udel.edu added the comment: If I understand, since the present patch uses present opcode semantics, adding a rotate, it could go into 2.7 and 3.2. Correct? 3.3 could get an improved patch that instead changed opcodes to expect key and value in the other order.

[issue11205] Evaluation order of dictionary display is different from reference manual.

Changes by Skip Montanaro s...@pobox.com: -- nosy: -skip.montanaro ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue11205 ___ ___ Python-bugs-list

[issue11205] Evaluation order of dictionary display is different from reference manual.

Changes by Raymond Hettinger raymond.hettin...@gmail.com: -- priority: normal - high ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue11205 ___ ___

[issue11205] Evaluation order of dictionary display is different from reference manual.

Changes by Éric Araujo mer...@netwok.org: -- nosy: +eric.araujo ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue11205 ___ ___ Python-bugs-list

[issue11205] Evaluation order of dictionary display is different from reference manual.

New submission from takayuki takayuki...@star.odn.ne.jp: Running the following code shows 2 1 4 3, but in reference manual http://docs.python.org/reference/expressions.html#expression-lists the evaluation order described as {expr1: expr2, expr3: expr4} def f(i): print i return i

[issue11205] Evaluation order of dictionary display is different from reference manual.

Changes by yeswanth swamiyeswa...@yahoo.com: -- nosy: +swamiyeswanth ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue11205 ___ ___ Python-bugs-list

[issue11205] Evaluation order of dictionary display is different from reference manual.

Skip Montanaro s...@pobox.com added the comment: Here's a patch. -- keywords: +patch nosy: +skip.montanaro versions: +Python 3.1, Python 3.2, Python 3.3 Added file: http://bugs.python.org/file20753/compile.diff ___ Python tracker

[issue11205] Evaluation order of dictionary display is different from reference manual.

Skip Montanaro s...@pobox.com added the comment: Working on a test case too. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue11205 ___ ___

[issue11205] Evaluation order of dictionary display is different from reference manual.

Changes by Skip Montanaro s...@pobox.com: Removed file: http://bugs.python.org/file20753/compile.diff ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue11205 ___

[issue11205] Evaluation order of dictionary display is different from reference manual.

Skip Montanaro s...@pobox.com added the comment: It's not so easy as first appeared. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue11205 ___

[issue11205] Evaluation order of dictionary display is different from reference manual.

Skip Montanaro s...@pobox.com added the comment: Okay, this looks better. I was confusing myself with leftover .pyc files I think. Test included. -- Added file: http://bugs.python.org/file20754/compile.diff ___ Python tracker rep...@bugs.python.org

[issue11205] Evaluation order of dictionary display is different from reference manual.

Skip Montanaro s...@pobox.com added the comment: Georg, I think this might need to sneak into 3.2. -- nosy: +georg.brandl ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue11205 ___

[issue11205] Evaluation order of dictionary display is different from reference manual.

Georg Brandl ge...@python.org added the comment: I don't think so -- it's a very minor deviation from the spec and not a critical bug. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue11205

[issue11205] Evaluation order of dictionary display is different from reference manual.

Skip Montanaro s...@pobox.com added the comment: 3.2 and earlier versions are all frozen, but for 3.3 it might make sense to bump the version number of the bytecode and change STORE_MAP to take the key and value in the opposite order, thus allowing to remove the ROT_TWO I had to add to make

[issue11205] Evaluation order of dictionary display is different from reference manual.

R. David Murray rdmur...@bitdance.com added the comment: Interesting. I would actually have expected the observed behavior. I think of the : in a dictionary literal as an assignment. -- nosy: +r.david.murray ___ Python tracker

[issue11205] Evaluation order of dictionary display is different from reference manual.

Georg Brandl ge...@python.org added the comment: BTW, it would be nice to know if this behavior was consistent with the docs at any time (the merge of the AST branch in 2.5 might be an obvious candidate where it was broken). Also interesting would be what other implementations of Python do.

[issue11205] Evaluation order of dictionary display is different from reference manual.

Skip Montanaro s...@pobox.com added the comment: As Georg suggested, it is correct in 2.4, wrong in 2.5. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue11205 ___

[issue11205] Evaluation order of dictionary display is different from reference manual.

Changes by Antoine Pitrou pit...@free.fr: -- nosy: +rhettinger ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue11205 ___ ___ Python-bugs-list

[issue11205] Evaluation order of dictionary display is different from reference manual.

Raymond Hettinger rhettin...@users.sourceforge.net added the comment: sigh If only a test had been checked-in eight years ago ... It looks like a number of things have to be changed in order to bring behavior back to what the docs promise. Dict literals and dict comprehensions need to be

[issue11205] Evaluation order of dictionary display is different from reference manual.

Raymond Hettinger rhettin...@users.sourceforge.net added the comment: takayuki, a special thanks to you for submitting such a well-researched bug report :-) -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue11205

[issue11205] Evaluation order of dictionary display is different from reference manual.

Skip Montanaro s...@pobox.com added the comment: To avoid introducing a ROT_TWO, the store STORE_MAP and MAP_ADD opcodes need minor modifications (just switch the u and w variable assignments). Either of which would not be possible in anything other that 3.3 or later, right? --

[issue11205] Evaluation order of dictionary display is different from reference manual.

Raymond Hettinger rhettin...@users.sourceforge.net added the comment: How much to change and how far to backport may make for a good python-dev discussion. ISTM that changing generated code goes hand-in-hand with changing opcode semantics (as long as the magic number gets bumped). OTOH,