new_contents: #!/usr/bin/env python
  
  import ROOT
  
  import alphatwirl
  
  from behind_scene import TwilightTree
  
  ##__________________________________________________________________||
  path = '/Users/sakuma/work/cms/c170327_twirl_tutorial/20170530_top/20170530_01_example_tree/TT_TuneCUETP8M2T4_13TeV-powheg-pythia8_ntuple_test.root'
  
  tfile = ROOT.TFile.Open(path)
  tree = tfile.Get('nTupleTree/tree')
  
  twtree = TwilightTree(tree)
  
  ##__________________________________________________________________||
  RoundLog = alphatwirl.binning.RoundLog
  tblcfg = [
      dict(
          valAttrNames = ('Event.Run', 'Event.LumiSection', 'Event.Number'),
          valOutColumnNames = ('run', 'lumi', 'event'),
          valIndices = (None, None, None)
      ),
      dict(
          valAttrNames = ('Event.Run', 'Event.LumiSection', 'Event.Number', 'Jets.Pt', 'Jets.Eta'),
          valOutColumnNames = ('run', 'lumi', 'event', 'jet_pt', 'jet_eta'),
          valIndices = (None, None, None, '(*)', '\\1')
      ),
  ]
  
  dataframes = twtree.scan(tblcfg = tblcfg, max_events = 10)
  
  for df in dataframes:
      print df.to_string(index = False)
  
  ##__________________________________________________________________||
  
subject: add a new example script example-scan.py