Server 20.04 verses 16.04: python-gnuplot

Bryce Harrington bryce.harrington at
Mon Jan 20 18:59:37 UTC 2020

On Mon, Jan 20, 2020 at 08:22:39AM -0800, Doug Smythies wrote:
> On 2020.01.19 17:03 Bryce Harrington wrote:
> > On Sun, Jan 19, 2020 at 04:24:13PM -0800, Doug Smythies wrote:
> I have not followed the issues, but am of the understanding that
> the transition from python 2 to 3 has not been easy.

It's certainly kept us busy.

> >  Looking at
> > the gnuplot package, it actually provides three variants:  gnuplot-x11,
> > gnuplot-qt, and gnuplot-nox.
> Oh.
> >  # apt-get install gnuplot-nox python3-gnuplot
> Yes, that seems to work, on a VM at least.
> It will be awhile yet until I repair the real test computer and try it for real.
> > Make sure your script is using python3 in its shbang:
> >
> >  #!/usr/bin/env python3
> Oh, that seems to be very important.
> I had just assumed that the existing "#!/usr/bin/python" would take care
> of version control issues. Maybe it eventually will for 20.04.
> Currently, I see it maps to python version 2 on a couple of computers,
> but doesn't exist on a 20.04 server VM I made for this e-mail thread.
> I also observe that somewhere along the way my new 20.04 server seems to
> have managed to get some of python 2 installed:

Some info on where things are at during development:

I gather around release they'll make some adjustments, so some of the
changes to e.g. remove the python shbang are being done more to make
problems more evident, and could change for the release.

> As for the kernel script example, and its prerequisites header:
> > Prerequisites:
> >     Python version 2.7.x
> >     gnuplot 5.0 or higher
> >     gnuplot-py 1.8    
> I'll change that to whatever is required moving forward and submit upstream.
> It just has to be distro independent, obviously.

The python3 shbang should be fine to most upstreams.  Where there might
be some difference of opinion is whether to call it like:

#!/usr/bin/env python3



The former is preferred for distro scripts.


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