merge.py

#!/usr/bin/env python
from ROOT import *
import sys,os, glob

runName = sys.argv[1]
fileList = glob.glob(runName+'_0[0-3][0-9].amp.root')

ml = TList()
for f in fileList:
  print f
  ff = TFile.Open(f)
  ml.Add(ff.Get('t'))
  
fout = TFile.Open(runName+'.amp.root', 'recreate')
fout.cd()
print 'merging files into', fout.GetName()
outTree = TTree.MergeTrees(ml,'fast')
outTree.Write()
fout.Close()