[issue39864] IndexError gives wrong axis info

[Ningyi Du]

Ningyi Du <ningyidu at gmail.com> added the comment:

I believe it's a bug. The axis 0 is misleading.  However, it is a problem
for numpy developers. Thank you for your time.

On Thu, Mar 5, 2020, 10:42 AM Peter Otten <report at bugs.python.org> wrote:

>
> Peter Otten <__peter__ at web.de> added the comment:
>
> This is not a bug (and if it were you would have to report to numpy, not
> cpython).
>
> Consider:
>
> >>> import numpy
> >>> a = numpy.zeros((2,2,2))
> >>> a[0,2]
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
> IndexError: index 2 is out of bounds for axis 1 with size 2
>
> This is probably the message you expect. However, if you write
> >>> a[0][2]
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
> IndexError: index 2 is out of bounds for axis 0 with size 2
>
> you split the operation into two steps, and the second axis of a is
> effectively the first axis of a[0].
>
> ----------
> nosy: +peter.otten -steven.daprano
>
> _______________________________________
> Python tracker <report at bugs.python.org>
> <https://bugs.python.org/issue39864>
> _______________________________________
>

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title: IndexError  gives wrong axis info -> IndexError gives wrong axis info

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue39864>
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