new_contents: #!/usr/bin/env python
  # Tai Sakuma <tai.sakuma@cern.ch>
  
  ##__________________________________________________________________||
  import os, sys
  import timeit
  import array
  import ROOT
  from AlphaTwirl.Events import Events, BEvents
  
  ##__________________________________________________________________||
  inputPath = 'tree.root'
  treeName = 'tree'
  
  ##__________________________________________________________________||
  def use_BEvents():
      inputFile = ROOT.TFile.Open(inputPath)
      tree = inputFile.Get(treeName)
      events = BEvents(tree)
      jet_pt = events.jet_pt
      trigger_path = events.trigger_path
      trigger_version = events.trigger_version
      for event in events:
          for i in range(len(jet_pt)):
              jet_pt[i]
          # print [v for v in trigger_path]
          # print [v for v in trigger_version]
  
  ##__________________________________________________________________||
  def use_SetBranchAddress():
      inputFile = ROOT.TFile.Open(inputPath)
      tree = inputFile.Get(treeName)
      tree.SetBranchStatus("*", 0)
      tree.SetBranchStatus("njet", 1)
      tree.SetBranchStatus("jet_pt", 1)
      tree.SetBranchStatus("trigger_path", 1)
      tree.SetBranchStatus("trigger_version", 1)
      maxn = 65536
      njet = array.array('i',[ 0 ])
      jet_pt = array.array('d', maxn*[ 0 ])
      tree.SetBranchAddress("njet" , njet)
      tree.SetBranchAddress("jet_pt" , jet_pt)
      trigger_path = ROOT.vector('string')()
      tree.SetBranchAddress("trigger_path", trigger_path)
      trigger_version = ROOT.vector('int')()
      tree.SetBranchAddress("trigger_version", trigger_version)
      for i in xrange(tree.GetEntries()):
          if tree.GetEntry(i) <= 0: break
          for i in range(njet[0]):
              jet_pt[i]
          # print [v for v in trigger_path]
          # print [v for v in trigger_version]
  
  ##__________________________________________________________________||
  ways = ['simplest_way', 'use_SetBranchStatus', 'use_GetLeaf', 'use_SetBranchAddress']
  ways = ['use_BEvents', 'use_SetBranchAddress', 'use_BEvents', 'use_SetBranchAddress']
  
  for w in ways:
      print w, ':',
      print timeit.timeit(w + '()', number = 1, setup = 'from __main__ import ' + w)
  
  ##__________________________________________________________________||
  
subject: add a tentative example file examples/ROOT/test_std_vector.py