| msg274813 - (view) |
Author: Ivan Levkivskyi (levkivskyi) *  |
Date: 2016-09-07 14:08 |
| The documentation at https://docs.python.org/3/reference/simple_stmts.html says that: "Names listed in a global statement must not be used in the same code block textually preceding that global statement" But then later: "CPython implementation detail: The current implementation does not enforce the two restrictions, but programs should not abuse this freedom, as future implementations may enforce them..." Code like this def f(): x = 1 global x gives SyntaxWarning for several releases, maybe it is time to make it a SyntaxError? |
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| msg274836 - (view) |
Author: Guido van Rossum (gvanrossum) * |
Date: 2016-09-07 16:58 |
| I like fixing this. I suppose it'll be fixed for nonlocal too? |
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| msg274888 - (view) |
Author: Ivan Levkivskyi (levkivskyi) * |
Date: 2016-09-07 20:51 |
| Yes, nonlocal will be fixed too. This will be a relatively small patch, but I am a bit afraid there could be merge conflicts (the code affected could overlap with changes for PEP 526). Easiest way would be to simply make this a single patch with PEP 526 implementation (this will actually even slightly simplify the implementation). Alternatively we could fix this right after the implementation patch is applied. What do you prefer? |
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| msg274894 - (view) |
Author: Guido van Rossum (gvanrossum) * |
Date: 2016-09-07 21:08 |
| I strongly prefer to have it as a separate patch (either before or after) to avoid the appearance of piggy-backing this in with a much larger change. |
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| msg274895 - (view) |
Author: Ivan Levkivskyi (levkivskyi) * |
Date: 2016-09-07 21:11 |
| OK, then I think after will be safer. Let us came back to this right after PEP 526. |
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| msg275314 - (view) |
Author: Ivan Levkivskyi (levkivskyi) * |
Date: 2016-09-09 12:13 |
| I am attaching the patch. Yury, I also added you here, just in case you have time for this. Btw, while working on this I have found that the second restriction: """ Names listed in a global statement must not be ... in a for loop control target, class definition, function definition, or import statement. """ is not enforced at all, it does not give even a SyntaxWarning. Is it something worth fixing? |
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| msg275318 - (view) |
Author: Ivan Levkivskyi (levkivskyi) * |
Date: 2016-09-09 14:18 |
| Added few tests to the patch |
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| msg275332 - (view) |
Author: Guido van Rossum (gvanrossum) * |
Date: 2016-09-09 16:25 |
| I'll commit this. |
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| msg275344 - (view) |
Author: Roundup Robot (python-dev)  |
Date: 2016-09-09 16:53 |
| New changeset 804b71d43c85 by Guido van Rossum in branch 'default': Issue #27999: Make "global after use" a SyntaxError, and ditto for nonlocal. https://hg.python.org/cpython/rev/804b71d43c85 |
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| msg275346 - (view) |
Author: Guido van Rossum (gvanrossum) * |
Date: 2016-09-09 16:53 |
| Thanks again Ivan! |
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