Undo cmsenv

eval `scram unsetenv -sh` #or -csh if you use c shell

pip in CMSSW

To include pip installed packages in cmsenv, try this link, which is available on LPC cluster, /cvmfs/cms-lpc.opensciencegrid.org/FNALLPC/lpc-scripts/. scram-pip installs for py2 by default. Make sure to do cmsenv again afterward to set up the python path.

In some old CMSSW versions, the pip package/library is there, but the executable isn't. Here is what you have to do:

HOME=$CMSSW_BASE python -m ensurepip --user
scram-pip -d $CMSSW_BASE/.local
cmsenv
HOME=$CMSSW_BASE pip install --no-cache-dir --user --upgrade pip

An alternative to grep and other software like grep

Try ripgrep. More details on this blog

Redirect root TTree::Scan()

See this post

root [0] ((TTreePlayer*)(ntuple->GetPlayer()))->SetScanRedirect(kTRUE);
root [1] ((TTreePlayer*)(ntuple->GetPlayer()))->SetScanFileName("output.txt");
root [2] ntuple->Scan();
File <output.txt> created
root [3] .! ls -l output.txt
-rw-r--r--  1 couet  staff  1825292 Sep  3 13:22 output.txt
root [4]

-- YousenZhang - 2020-10-01