[issue27494] 2to3 parser failure caused by a comma after a generator expression

Łukasz Langa added the comment: This is one of those issues where it's clear that the parser and 2to3 should be separate. -- nosy: +lukasz.langa ___ Python tracker ___

[issue27494] 2to3 parser failure caused by a comma after a generator expression

Jakub Stasiak added the comment: I appreciate the example, but I'd claim that's a "missing fixer" issue, not a "parser accepts too much" issue. Considering the syntax wasn't ambiguous (I think) and had been accepted before 3.7 I'll remain not totally convinced here. --

[issue27494] 2to3 parser failure caused by a comma after a generator expression

Serhiy Storchaka added the comment: Sorry, I missed that you didn't receive a notification about creating of the reverting PR. I should announce this explicitly. 2to3 handles the old syntax, but a comma after a generator expression was not a valid old syntax. With your patch it accepted

[issue27494] 2to3 parser failure caused by a comma after a generator expression

Jakub Stasiak added the comment: Apologies for only responding now, I've not received any notifications after my original pull request had been merged. I only learned about the change being reverted from https://github.com/python/cpython/pull/8580, so let me leave my two cents here: I

[issue27494] 2to3 parser failure caused by a comma after a generator expression

miss-islington added the comment: New changeset 9ecbe3321f7bb3726017a053e583ca507d4453fc by Miss Islington (bot) in branch '3.7': Revert "closes bpo-27494: Fix 2to3 handling of trailing comma after a generator expression (GH-3771)" (GH-8241)

[issue27494] 2to3 parser failure caused by a comma after a generator expression

Serhiy Storchaka added the comment: New changeset 4b8a7f51da224d1a0ad8159935f78ba4e6e16037 by Serhiy Storchaka in branch 'master': Revert "closes bpo-27494: Fix 2to3 handling of trailing comma after a generator expression (GH-3771)" (#8241)

[issue27494] 2to3 parser failure caused by a comma after a generator expression

Change by miss-islington : -- pull_requests: +8088 ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe:

[issue27494] 2to3 parser failure caused by a comma after a generator expression

Change by Serhiy Storchaka : -- pull_requests: +7773 stage: -> patch review ___ Python tracker ___ ___ Python-bugs-list mailing

[issue27494] 2to3 parser failure caused by a comma after a generator expression

Change by Serhiy Storchaka : -- type: crash -> behavior versions: +Python 3.8 -Python 2.7, Python 3.5, Python 3.6 ___ Python tracker ___

[issue27494] 2to3 parser failure caused by a comma after a generator expression

Serhiy Storchaka added the comment: Since this syntax never was valid according to the Python language specification, and it causes SyntaxError in 3.7 (see issue32012), I think that this change should be reverted. -- resolution: fixed -> stage: resolved

[issue27494] 2to3 parser failure caused by a comma after a generator expression

Serhiy Storchaka added the comment: Actually this syntax isn't allowed by the Python language specification. See issue32012 for fixing the Python parser. -- ___ Python tracker

[issue27494] 2to3 parser failure caused by a comma after a generator expression

Benjamin Peterson added the comment: New changeset af810b35b494ef1d255d4bf340b92a9dad446995 by Benjamin Peterson (Jakub Stasiak) in branch 'master': closes bpo-27494: Fix 2to3 handling of trailing comma after a generator expression (#3771)

[issue27494] 2to3 parser failure caused by a comma after a generator expression

Jakub Stasiak added the comment: By "forbid" do you mean "forbid in Python" (as in change Python syntax)? I like the idea but that seems like a more serious change and 2to3 arguably needs to handle code targeting older Python versions anyway. --

[issue27494] 2to3 parser failure caused by a comma after a generator expression

Changes by Jakub Stasiak : -- keywords: +patch pull_requests: +3758 stage: -> patch review ___ Python tracker ___

[issue27494] 2to3 parser failure caused by a comma after a generator expression

Serhiy Storchaka added the comment: set(x for x in range(2),) can be interpreted as set(x for x in (range(2),)). Wouldn't be better to forbid such ambiguous syntax? The trailing comma in argument list is supported because it helps to add new arguments (or temporary comment out arguments).

[issue27494] 2to3 parser failure caused by a comma after a generator expression

Cheryl Sabella added the comment: Adding benjamin.peterson as he is listed as the expert for 2to3. -- nosy: +benjamin.peterson, csabella ___ Python tracker

[issue27494] 2to3 parser failure caused by a comma after a generator expression

Changes by Jakub Stasiak : -- versions: +Python 3.6, Python 3.7 ___ Python tracker ___

[issue27494] 2to3 parser failure caused by a comma after a generator expression

Changes by Jakub Stasiak : -- pull_requests: +87 ___ Python tracker ___ ___

[issue27494] 2to3 parser failure caused by a comma after a generator expression

Changes by John Mark Vandenberg : -- nosy: +jayvdb ___ Python tracker ___ ___

[issue27494] 2to3 parser failure caused by a comma after a generator expression

New submission from Jakub Stasiak: Test file (test.py): print(set(x for x in range(2),)) Python runs it nicely: % python2 test.py set([0, 1]) % python3 test.py {0, 1} 2to3 parser (on both Python 2.7.11 and 3.5.2) chokes on it though: %