I've tried now and it works correctly. Maybe updating some python packages fixed the problem.
On Fri, Apr 8, 2016 at 8:06 PM Filipe Saraiva via KDE Bugzilla <bugzilla_noreply@kde.org> wrote:

> https://bugs.kde.org/show_bug.cgi?id=359927
> --- Comment #1 from Filipe Saraiva <filipe@kde.org> ---
> Hello Simone, I can not to reproduce this bug. Please, can you verify if you
> have this bug yet?
> I run the follow commands:
> x = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
> from matplotlib import pylab
> pylab.clf()
> pylab.plot(x)
> pylab.show()
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