PileUp ReWeighting

First, update lumiJSON in ''CatProducer/python/catDefinitions_cfi.py''. Don't put '.txt'. In lxplus or afs enabled server

getJSONAndPuWeights.py -l Cert_314472-325175_13TeV_PromptReco_Collisions18_JSON.txt

This will produce a 'pileupWeight.py' file

In your analysis/ntupler cfg file, insert

process.load("CATTools.CatProducer.pileupWeight_cff")                # loads pileup weighting tool
from CATTools.CatProducer.pileupWeight_cff import pileupWeightMap
process.pileupWeight.weightingMethod = "RedoWeight"                  # set mode to reweighting
process.pileupWeight.pileupMC = pileupWeightMap["Startup2015_25ns"]  # MC pileup distrubition 
from pileup import pileupMap                                         # new pileup file made with getPileUpData.py
process.pileupWeight.pileupRD = pileupMap["Cert_246908-260627_13TeV_PromptReco_Collisions15_25ns_JSON"] # new data PU distrubition
process.pileupWeight.pileupUp = pileupMap["Cert_246908-260627_13TeV_PromptReco_Collisions15_25ns_JSON_Up"]
process.pileupWeight.pileupDn = pileupMap["Cert_246908-260627_13TeV_PromptReco_Collisions15_25ns_JSON_Dn"]


process.p = cms.Path(process.pileupWeight + process.yourcode)