new_contents: #!/usr/bin/env python
  
  import sys
  import json
  from math import sqrt
  
  def mean_and_sd(iterable):
      mean = sum(iterable) / len(iterable)
      sd = 0
      if len(iterable) > 1:
          sd = sqrt(sum([ (x - mean)**2 for x in iterable]) / (len(iterable) - 1))
      return (mean, sd)
  
  class JobMetricAccumulator:
      def __init__(self):
          self.cpu = list()
          self.ram = list()
          self.wall = list()
  
      def process_json(self, json):
          self.cpu.append(json['CpuUsed'] / 60.0)
          self.ram.append(json['MaxMem'] / 1000.0)
          self.wall.append(json['RunTime'] / 60.0)
  
      def __str__(self):
          results = list()
          means_and_sd = map(mean_and_sd, (self.wall, self.cpu, self.ram))
          for x in means_and_sd:
              results.append(x[0])
              results.append(x[1])
          return "Wall(m): {0} +/- {1}\nCPU(m): {2} +/- {3}\nRAM(M): {4} +/- {5}\n".format(*results)
  
  accumulator = JobMetricAccumulator()
  
  doc = json.load(sys.stdin)
  for job in doc:
      accumulator.process_json(job)
  
  print accumulator
  
subject: make a nice table of results from output of @idas bmetrica tool