Steven D'Aprano <steve+pyt...@pearwood.info> added the comment: On Sun, Dec 10, 2017 at 09:15:16AM +0000, Serhiy Storchaka wrote: > My point is that the current error message is correct and is not misleading.
With respect Serhiy, in this bug report you have TWO PEOPLE who have said that it is misleading in this context -- the person who raised the bug report, and me. It might not be misleading to you, but it mislead us. I've been using Python for over a decade and a half, and when I read the exception it confused me too: why is the for loop trying to iterate over a Fraction? Did the generator accidentally call return instead of yield? I was especially confused because I was expecting a ValueError too many/too few values to unpack. Of course, with a bit more thought I realised that the error isn't generated by the for loop, but the unpacking. 15 years of reading exceptions does count for something :-) If you prefer "lacking sufficient information" over misleading, I won't disagree. Putting aside pointless quibbles over the exact wording of *why* the current error message is suboptimal, I hope that we can all agree that if the error occurs during an unpacking operation, the error message should preferably say that the object cannot be unpacked. Is there any advantage to not giving that information if we can? > And this is a standard error message raised in many other cases. There > is no a bug. I agreed that it isn't a bug, and changed this to an enhancement. Better error messages should be welcomed, not rejected because they aren't fixing a bug. > *Maybe* it can be improved in some specific cases. Do you want to > provide a patch Steven? Without concrete patch the following > discussion doesn't make sense. We even don't know if such patch is > possible. Someone who knows C and the interpreter internals better than me will have to provide a patch. I wouldn't even know where to start looking. But my guess would be the UNPACK_SEQUENCE op-code. ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue32259> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
