Useful Tips in analysis

Python tips

• When you want to input huge files into your cfg file, if you know the directory, you don't need to write all of them on the cfg file. Just replace like this

at lxplus :
=========
# Input source
process.source = cms.Source("PoolSource",
   skipEvents = cms.untracked.uint32(0),
    fileNames = cms.untracked.vstring(),
      duplicateCheckMode = cms.untracked.string('noDuplicateCheck'),
   dropDescendantsOfDroppedBranches=cms.untracked.bool(False)
)
import os,commands
# get a list of files from a specified directory
mydir = "/castor/cern.ch/user/d/dmoon/cms390pre5/Hydjet_MinBias_2.76TeV_Z0_Flat_Emb_HLT"
cmd  = 'nsls %s/ ' % (mydir)
mylist = ["rfio:%s/%s" % (mydir,j) for j in commands.getoutput(cmd).split('\n')]

# add a specified number of files from mydir to the list of fileNames
nfiles=300 #number from "ls mydir |wc"
for i in range(0,nfiles):
    process.source.fileNames.append('%s' % (mylist[i]))
    print "process.source.fileNames.append(%s" % (mylist[i])
    print "Number of files to process is %s" % (len(process.source.fileNames))
=========

at mit
============
# Input source
process.source = cms.Source("PoolSource",
   skipEvents = cms.untracked.uint32(0),
    fileNames = cms.untracked.vstring(),
      duplicateCheckMode = cms.untracked.string('noDuplicateCheck'),
   dropDescendantsOfDroppedBranches=cms.untracked.bool(False)
)
import os, commands
# get a list of files from a specified directory
mydir = "/pnfs/cmsaf.mit.edu/t2bat/cms/store/user/davidlw/Hydjet_Quenched_MinBias_2760GeV_START39V0_GEN_SIM_RAW_390pre5/SingleJPsimumu_FlatPt0to20_START39V1_GEN_SIM_RAW_390pre5/90920f11cf28a60a1a989824b938abb3/"
mylist = os.listdir(mydir)

# add a specified number of files from mydir to the list of fileNames
nfiles=5 # number from "ls mydir |wc
for i in range(0,nfiles):
  process.source.fileNames.append('dcache:%s/%s' % (mydir,mylist[i]))

-- DongHoMoon - 11 Oct 2010