| msg203796 - (view) |
Author: Brett Cannon (brett.cannon) *  |
Date: 2013-11-22 16:25 |
| So that e.g. __main__.__spec__.name is the actual name of the module being executed. |
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| msg203945 - (view) |
Author: Eric Snow (eric.snow) * |
Date: 2013-11-23 01:23 |
| I've already started on this somewhat. However, I'm going to close out more of the other PEP 451 issues before going any further. Nick: when do you think things will settle down that you could field a question or two and some reviews relative to the __main__ changes. I keep wondering if I'll have inadvertently implemented good chunks of PEP 395 by the time I'm done here. |
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| msg204030 - (view) |
Author: Alyssa Coghlan (ncoghlan) * |
Date: 2013-11-23 14:27 |
| Yes, PEP 451 addresses a few of the PEP 395 issues. Between this and PEP 420, I actually plan to withdraw that PEP as out of date. All my pre-beta commits are done, so ask away :) |
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| msg207267 - (view) |
Author: Eric Snow (eric.snow) * |
Date: 2014-01-04 07:09 |
| Here's an outline of how I see __main__.__spec__ playing out relative to the various cmdline interfaces. == == == === ==== ======== ======== ======== ======== ============ - -c -m dir file name loader origin cached has_location == == == === ==== ======== ======== ======== ======== ============ __main__ builtin - None False X __main__ builtin - None False X __main__ builtin -c None False X (finder) (finder) (finder) (finder) (finder) X __main__ path None True X __main__ path None True == == == === ==== ======== ======== ======== ======== ============ Note: __main__.__spec__ in the -m case is addressed in issue #19700. Thoughts? See: [1] http://docs.python.org/3.4/using/cmdline.html [2] Python/pythonrun.c [3] Modules/main.c |
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| msg207268 - (view) |
Author: Eric Snow (eric.snow) * |
Date: 2014-01-04 07:10 |
| For the record, normal start-up happens like this (simplified): 1. prep for and create/initialize interpreter 2. exec the site module in the __main__ namespace (unless -S) 3. do the interface-specific stuff Note: exec of the site module does not impact the spec. In the case where -i/PYTHONINSPECT is issued (or implied): 1. ... 2. ... 3. exec the PYTHONSTARTUP script (if set and it exists) 4. do the interface-specific stuff 5. start the REPL Note: the -i case does not impact the spec, nor does the exec of any PYTHONSTARTUP script. See: [1] http://docs.python.org/3.4/using/cmdline.html [2] Python/pythonrun.c [3] Modules/main.c [4] PEP 432 |
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| msg207269 - (view) |
Author: Eric Snow (eric.snow) * |
Date: 2014-01-04 07:14 |
| Food for thought: We could (for 3.5) add an importer just for __main__ that gives us the appropriate spec and loads __main__ accordingly. Such a loader could even incorporate exec of the site module (and any PYTHONSTARTUP script). |
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| msg207271 - (view) |
Author: Alyssa Coghlan (ncoghlan) * |
Date: 2014-01-04 07:45 |
| You'd also need to update the new multiprocessing code - it currently expects "__main__.__spec__ == None" for all the run-from-a-path-or-stdin cases. The -m switch and running __main__ from a supplied sys.path entry (the "dir" entry in your table) are both already handled by the runpy changes in issue 19700. The remaining cases where __main__.__spec__ is currently None: - interactive prompt - -c switch - running from stdin - running directly from a source or bytecode file To be honest, I'm not sure it actually makes sense to try to manufacture a pseudo-spec for those cases. A main script may not be importable as a module (e.g. a hyphen in its name, or no .py suffix), and you *definitely* can't import a file that doesn't exist on disk (REPL, stdin, -c). |
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| msg207272 - (view) |
Author: Eric Snow (eric.snow) * |
Date: 2014-01-04 08:09 |
| I'm fine with leaving __spec__ as None for those remaining cases. It definitely simplifies this ticket. :) Do you see any reason to not close this one at this point? |
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| msg207273 - (view) |
Author: Alyssa Coghlan (ncoghlan) * |
Date: 2014-01-04 08:20 |
| I think we need to document this somewhere. Not exactly sure where though - a new subsection in the import reference, perhaps? |
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| msg215078 - (view) |
Author: Eric Snow (eric.snow) * |
Date: 2014-03-28 21:29 |
| Here's a basic patch. It introduces __main__ in import.rst and then identifies the cases where __spec__ is set to None or otherwise. There are a few :ref: links to labels on other pages that I had trouble with. I'll address those when I put up a new draft after feedback. Any suggestions on making them work would be helpful. :) |
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| msg215093 - (view) |
Author: Alyssa Coghlan (ncoghlan) * |
Date: 2014-03-28 23:31 |
| Looks like a reasonable general structure to me. For label references, you don't want to include the leading underscore - that's part of the label syntax, not the label itself. |
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| msg215098 - (view) |
Author: Eric Snow (eric.snow) * |
Date: 2014-03-28 23:46 |
| That did the trick, Nick. I swear there's always something I forget about ReST. :) Otherwise do you have any objections to the patch? I imagine there's more we could put in the section (for language spec purposes), but I figure what I have there is good enough for the moment. |
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| msg215099 - (view) |
Author: Alyssa Coghlan (ncoghlan) * |
Date: 2014-03-28 23:48 |
| "is some cases" is a typo, but otherwise, yeah, may as well commit this so the website gets updated while we decide what else (if anything) we want to cover. |
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| msg215100 - (view) |
Author: Roundup Robot (python-dev)  |
Date: 2014-03-29 00:11 |
| New changeset 21d8222b667f by Eric Snow in branch 'default': Issue #19697: Document cases where __main__.__spec__ is None. http://hg.python.org/cpython/rev/21d8222b667f |
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| msg215101 - (view) |
Author: Roundup Robot (python-dev) |
Date: 2014-03-29 00:30 |
| New changeset 4972475ae2e7 by Eric Snow in branch '3.4': Issue #19697: Document cases where __main__.__spec__ is None. http://hg.python.org/cpython/rev/4972475ae2e7 |
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| msg215102 - (view) |
Author: Eric Snow (eric.snow) * |
Date: 2014-03-29 00:32 |
| Wish I had done that in the opposite direction. Anyway, thanks Nick. |
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| msg215114 - (view) |
Author: Roundup Robot (python-dev) |
Date: 2014-03-29 05:41 |
| New changeset 0427c2ff653d by Nick Coghlan in branch '3.4': Issue #19697: document more __main__.__spec__ quirks http://hg.python.org/cpython/rev/0427c2ff653d New changeset a90254be2da2 by Nick Coghlan in branch 'default': Issue #19697: merge docs from 3.4 http://hg.python.org/cpython/rev/a90254be2da2 |
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