[Python-Dev] %x formatting of floats - behaviour change since 3.4

[Chris Angelico]

On Wed, Jun 4, 2014 at 8:26 AM, Glenn Linderman <v+python at g.nevcal.com> wrote:
> On 6/3/2014 3:05 PM, Chris Angelico wrote:
>
> On Wed, Jun 4, 2014 at 8:03 AM, Victor Stinner <victor.stinner at gmail.com>
> wrote:
>
> 2014-06-03 23:38 GMT+02:00 Chris Angelico <rosuav at gmail.com>:
>
> Is this an intentional change? And if so, is it formally documented
> somewhere? I don't recall seeing anything about it, but my
> recollection doesn't mean much.
>
> Yes, it's intentional. See the issue for the rationale:
> http://bugs.python.org/issue19995
>
> Thanks! I'll fix (in this case, simply remove) the test and cite that issue.
>
>
> Wouldn't it be better to keep the test, but expect the operation to fail?

The way micropython does its tests is: Run CPython on a script, then
run micropython on the same script. If the output differs, it's an
error. The problem is, CPython 3.3 and CPython 3.5 give different
output (one gives an exception, the other works as if int(x) had been
given), so it's impossible for the test to be done right.

My question was mainly to ascertain whether it's the tests or my
system that needed fixing.

ChrisA