[Numpy-discussion] changing ValueError to KeyError for bad field access

[Allan Haldane]

Hi all,

I think it would be very nice to make access to invalid fields of a

a = np.ones(3, dtype=[('a', 'f4'), ('b', 'f4')])
a['c']

KeyError: 'c'

A commit in my PR https://github.com/numpy/numpy/pull/5636 does this. As
discussed there, backwards compatibility is a problem but it seems like
the impact might be fairly small.

Any opinions?

Allan

[Sturla Molden]

Post by Allan Haldane

a = np.ones(3, dtype=[('a', 'f4'), ('b', 'f4')])
a['c']

KeyError: 'c'
Any opinions?

Sounds good to me. But it will probably break someones code.


Sturla

[Phil Hodge]

Post by Allan Haldane
I think it would be very nice to make access to invalid fields of a

a = np.ones(3, dtype=[('a', 'f4'), ('b', 'f4')])
a['c']

KeyError: 'c'

This will break code, but it should do so in a way that's visible.
KeyError does seem like a more appropriate exception to me.

Phil