post-ap 0.2.3

Project with code needed to filter, trim and slim ntuples produced by AP

Description

This project is used to:

• Filter, slim, trim the trees from a given AP production
• Rename branches

This is done using configurations in a YAML file and through Ganga jobs.

Installation

This project cannot be installed and used from within a virtual environment. It depends on Ganga and therefore one has to be installed in $HOME/.local/ for this do:

. cvmfs/lhcb.cern.ch/lib/LbEnv

# Will install a few projects on top of what is already in the LHCb environment
pip install post_ap

# Make a proxy that lasts 100 hours
lhcb-proxy-init -v 100:00

In order to make Ganga aware of the post_ap package do:

import sys
import os

home_dir = os.environ['HOME']
sys.path.append(f'{home_dir}/.local/lib/python3.12/site-packages')
sys.path.append('/cvmfs/lhcb.cern.ch/lib/var/lib/LbEnv/3386/stable/linux-64/lib/python3.12/site-packages')

in .ganga.py, where the path will depend on the version of python used by the LHCb environment.

To check that this is working, open ganga and run:

from post_ap.pfn_reader        import PFNReader

Submitting jobs

For this one would run a line like:

job_filter_ganga -n job_name -p PRODUCTION -s SAMPLE -c /path/to/config/file.yaml -b BACKEND -v VERSION_OF_ENV 

• The number of jobs will be equal to the number of PFNs, up to 500 jobs.
• The code used to filter reside in the grid and the only thing the user has to do is to provide the latest version

Check latest version of virtual environment

The jobs below will run with code from a virtual environment that is already in the grid. One should use the latest version of this environment. To know the latest versions, run:

# In a separate terminal open a shell with access to dirac
post_shell

# Run this command for a list of environmets
list_venvs

The post_shell terminal won't be used to send jobs.

Config file

Here is where all the configuration goes and an example of a config can be found here

Optional

• In order to improve the ganga experience use:

# Minimizes messages when opening ganga
# Does not start monitoring of jobs by default
alias ganga='ganga --quiet --no-mon'

in the $HOME/.bashrc file. Monitoring can be turned on by hand as explained here