| msg410204 - (view) |
Author: Irit Katriel (iritkatriel) *  |
Date: 2022-01-10 11:50 |
| Following to changes in , the interpreter's internal representation of the active exception is just the exception instance (the exc_type and exc_traceback fields were removed). For backwards compatibility, sys.exc_info() constructs the (typ, val, tb) tuple from the instance and this will continue to be the case for some time because this tuple has leaked into quite a few APIs. However, now that the redundancy in the exc_info tuple is guaranteed by the way it's constructed, we can confidently add a sys.exception() method that returns just the exception instance (as suggested in PEP3134's section on future improvements). This small change will make a difference to learners because the (typ, val, tb) tuple looks quite cryptic to those who don't know about tracebacks, and the redundancy in it is confusing for those who do. |
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| msg410216 - (view) |
Author: Irit Katriel (iritkatriel) * |
Date: 2022-01-10 14:00 |
| This is part of a larger plan to reduce the footprint of the exc_info triplet on the language. See https://gist.github.com/iritkatriel/3927147548b10a7929cb0b680e3adc52 History |
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| msg410222 - (view) |
Author: Dennis Sweeney (Dennis Sweeney) * |
Date: 2022-01-10 15:33 |
| Would there be any value in spelling this as sys.active_exception() or sys.current_exception() or sys.get_exception() or sys.exception_in_flight() or similar? My only worry is confusion between sys.exception() versus builtins.Exception. |
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| msg410224 - (view) |
Author: Eric Snow (eric.snow) * |
Date: 2022-01-10 16:10 |
| So sys.exception() will be equivalent to sys.exc_info()[1] (or rather, sys.exc_info() will be (type(sys.exception()), sys.exception(), sys.exception().__traceback__))? That seems good to me. |
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| msg410225 - (view) |
Author: Eric Snow (eric.snow) * |
Date: 2022-01-10 16:10 |
| FWIW, here's an alternative we should *not* pursue: return just the exception from sys.exc_info(). For compatibility, we would implement `__iter__` and `__getitem__` on BaseException, to duplicate the behavior of the current tuple. There are a number of good reasons why this is *not* what we should do. |
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| msg410255 - (view) |
Author: Irit Katriel (iritkatriel) * |
Date: 2022-01-10 21:29 |
| I thought of something like sys.active_exception() but it seems like a lot to type. sys.exception() was suggested in pep3134. Does this change need a pep? |
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| msg410258 - (view) |
Author: Barry A. Warsaw (barry) * |
Date: 2022-01-10 21:50 |
| sys.exception() seems like a decent enough trade-off. I've always disliked the abbreviations in "exc_info". It doesn't feel big enough for a PEP to me. |
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| msg410260 - (view) |
Author: Irit Katriel (iritkatriel) * |
Date: 2022-01-10 22:00 |
| Cool. I just removed the do-not-merge label from the PR and I guess it's ready to be reviewed. |
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| msg410489 - (view) |
Author: Irit Katriel (iritkatriel) * |
Date: 2022-01-13 12:36 |
| New changeset c590b581bba517f81ced2e6f531ccc9e2e22eab5 by Irit Katriel in branch 'main': bpo-46328: Add sys.exception() (GH-30514) https://github.com/python/cpython/commit/c590b581bba517f81ced2e6f531ccc9e2e22eab5 |
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