Issue 36000: debug is a keyword but not a keyword (original) (raw)

Issue36000

Created on 2019-02-15 12:22 by bup, last changed 2022-04-11 14:59 by admin. This issue is now closed.

Messages (5)
msg335605 - (view)	Author: Dan Snider (bup) *	Date: 2019-02-15 12:22
keyword.py is used by stuff like the idle colorizer to help determine if an identifier is considered a keyword but it doesn't identify __debug__ despite the fact that the parser treats it exactly the same as None, True, and False. I could not find a more recent issue to bring this back up than #34464 and there it was suggested a issue be made so here it is. As mentioned on that previous issue, currently keyword.py builds the list automatically by scanning "Python/graminit.c" but since there is no "__debug__" token to be found in that file it doesn't get added to kwlist. There is a file that groups the keywords True, False, None, and __debug__: ast.c. But there's no reason for it to be that complicated when nothing would break by for example adding on line 54 of keyword.py the statement "kwlist += ['__debug__']? Actually, I'm interested in knowing why __debug__ is a keyword in the first place. I'm terrible at searching apparently so there might be more but from what I can tell, the only thing the docs have to say about __debug__ really is the following tautology: "The value for the built-in variable [__debug__] is determined when the interpreter starts."
msg335606 - (view)	Author: Steven D'Aprano (steven.daprano) *	Date: 2019-02-15 12:40
I'm not sure that __debug__ is a proper keyword. Unlike None, if you monkey-patch builtins, you can modify it: py> builtins.__dict__['__debug__'] = 'Surprise!' py> __debug__ 'Surprise!' py> builtins.__dict__['None'] = 'Surprise!' py> None py> And it is not listed here: https://docs.python.org/3.7/reference/lexical_analysis.html#keywords So __debug__ appears to me to be in a strange grey area, part regular name and part keyword, but not quite either.
msg335685 - (view)	Author: Karthikeyan Singaravelan (xtreak) *	Date: 2019-02-16 14:10
See also
msg358767 - (view)	Author: Batuhan Taskaya (BTaskaya) *	Date: 2019-12-21 08:34
import builtins builtins.__dict__['__debug__'] = 'Surprise!' builtins.__dict__['None'] = 'Surprise!' print(__debug__) print(None) $ ./python ../t.py True None I guess this is related to Python/ast_opt.c transformation case Name_kind: if (_PyUnicode_EqualToASCIIString(node_->v.Name.id, "__debug__")) { return make_const(node_, PyBool_FromLong(!optimize_), ctx_); } break;
msg362482 - (view)	Author: Cheryl Sabella (cheryl.sabella) *	Date: 2020-02-22 23:08
Serhiy wrote in that __debug__ isn't a keyword and the error message was changed in 3.8. Due to that, I'm going to close this as not a bug.