[Python-Dev] TypeError messages (original) (raw)

Antoine Pitrou solipsis at pitrou.net
Sat Feb 21 18:14:22 CET 2015

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.

Regards

Antoine.

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