[Python-Dev] TypeError messages

Brett Cannon brett at python.org
Sat Feb 21 19:03:05 CET 2015


On Sat Feb 21 2015 at 12:15:25 PM Antoine Pitrou <solipsis at pitrou.net>
wrote:

> On Fri, 20 Feb 2015 14:05:11 +0000
> Brett Cannon <brett at python.org> wrote:
> > On Thu Feb 19 2015 at 5:52:07 PM Serhiy Storchaka <storchaka at gmail.com>
> > wrote:
> >
> > > Different patterns for TypeError messages are used in the stdlib:
> > >
> > >      expected X, Y found
> > >      expected X, found Y
> > >      expected X, but Y found
> > >      expected X instance, Y found
> > >      X expected, not Y
> > >      expect X, not Y
> > >      need X, Y found
> > >      X is required, not Y
> > >      Z must be X, not Y
> > >      Z should be X, not Y
> > >
> > > and more.
> > >
> > > What the pattern is most preferable?
> > >
> >
> > My preference is for "expected X, but found Y".
>
> If we are busy nitpicking, why are we saying "found Y"? Nothing was
> *found* by the callee, it just *got* an argument.
>
> So it should be "expected X, but got Y".
>
> Personally, I think the "but" is superfluous: the contradiction is
> already implied, so "expected X, got Y" is terser and conveys the
> meaning just as well.
>

I'm also fine with the terser version.

-Brett
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/python-dev/attachments/20150221/0213a947/attachment.html>


More information about the Python-Dev mailing list