text: #! /usr/bin/env python
  import sys
  import argparse
  parser = argparse.ArgumentParser()
  parser.add_argument("-a","--alpha",type=float,dest="alpha", metavar="FLOAT",default=1.0)
  parser.add_argument("--redteam",action="store_true")
  args = parser.parse_args()
  alpha=args.alpha
  
  ### MAP-REDUCE: compute the minimum p-value for each edge
  
  ## MAPPER:
  # - input: string "destination computer \t source computer \t left_pval \t right_pval"
  # - output: string "source computer _ destination computer \t left_pval _ right_pval"
  
  for line in sys.stdin:
      x=line.strip().split(",")
      src_computer = x[1]
      dst_computer = x[0]
      lpval = x[2]
      rpval = x[3]
      print src_computer+"_"+dst_computer+"\t"+lpval+"_"+rpval
  
  