[Numpy-discussion] Uncomfortable with matrix change

[Gael Varoquaux]

On Fri, May 09, 2008 at 12:53:40PM -0500, Nathan Bell wrote:
> True, but scipy.sparse makes fairly limited use of matrix and I have
> 386 unittests to tell me what broke.  End-users might spend
> considerably longer sorting out the problem, particularly if they
> don't know what they're looking for.  Personally, I would not have
> thought a 1.0 -> 1.1 version bump would break something like this.
> Yes, we can put caveats in the release notes, but how many
> numpy.matrix users read those?

Exact. Don't break existing code, or users will hate you, and eventually
stop using your code. In real life, many of the domain-specific libraries
still use numeric or numarray. People like to write code, and forget
about it for 10 years. If you change APIs they cannot do this.

> Alan, I don't fundamentally disagree with your positions on the
> deficiencies/quirks of matrices in numpy.  However, it's completely
> inappropriate to plug one hole while creating others, especially in a
> minor release.   I suspect that if we surveyed end-users we'd find
> that "my code still works" is a much higher priority than "A[0][0] now
> does what I expect".

+1. Pluging one annoyance to create another one (IMHO worse), and in
addition breaking backward compatibility seems utterly wrong to me.

Gaël