Install Ancil python version problem

1

Hi,

I’ve generated an error I haven’t seen before with a suite (u-cu408) which was working fine previously.

File “/work/n02/n02/jweber/cylc-run/u-cu408/app/install_ancil/bin/create_ancil_links.py”, line 86
print ‘Link {0} to {1}’.format(link, target)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
SyntaxError: Missing parentheses in call to ‘print’. Did you mean print(…)?
[FAIL] create_ancil_links.py <<‘STDIN’
[FAIL]
[FAIL] ‘STDIN’ # return-code=1
2023-03-21T14:22:27Z CRITICAL - failed/EXIT

This looks like a python version error. I think this may have come about as made some changes to the python environment because I wanted to use cf python on Archer2 to extract particular fields before transferring model output to Jasmin to save space and reduce transfer time. I ran the commands in Section 1-4 of this Reducing UM-UKCA data output using flight-track simulation document first in my work (incorrectly) and then in home (correctly).

cfpython is now working on Archer2 but do I need to need to switch back to a different python version to run UKESM?

Cheers,

James

2

Hi James,

Yes you are correct this is a python version error.

The install_ancil/bin/create_ancil_links.py will use the version of python in your login environment; so if you’ve change it from the default python2 to python3 then it will fail.

I would suggest removing the python version change from your ~/.bashrc or ~/.bash_profile and only load it into your login session when you need it.

Regards,
Ros.

3

Thanks, Ros, that makes sense. Once a suite has starting running on coupled, would it be ok to change python versions or will a suite need the same python version for the whole course of its run?

Cheers,

James

4

Each task will load your environment afresh when it is submitted to A2. It doesn’t remember what it loaded in a previous task or cycle.

However, install_ancil is only called once at the beginning of the run, so assuming there are no other tasks that need python2 you should be ok.

5

Great, thanks Ros.