json2tsv

#!/usr/bin/env python

import sys, getopt, json
from types import NoneType

def usage(name):
  print 'Usage: %s -l [key1:key2] -t [text1] -f [field1] -f [field2] ... -t [textN] -f [fieldN]' % name

def main(argv):
  fields = []
  nodeAddr = ''
  try:
    opts, args = getopt.getopt(argv[1:],'hl:f:t:')
  except getopt.GetoptError:
    usage(argv[0])
    sys.exit(2)
  for opt, arg in opts:
    if opt in ('-h'):
      usage(argv[0])
      sys.exit()
    elif opt in ('-f'):
      fields.append(['f', arg])
    elif opt in ('-t'):
      fields.append(['t', arg])
    elif opt in ('-l'):
      nodeAddr = arg
  if not nodeAddr or not fields:
    usage(argv[0])
    sys.exit(1)
  pipe = sys.stdin.read()
  try:
    payload = json.loads(pipe)
  except:
    print 'Err: unable to parse JSON'
    sys.exit(1)
  nodeList = nodeAddr.split(':')
  data = []
  for i in nodeList:
    if i in payload.keys():
      data = payload[i]
    else:
      print 'Err: unable to find a list "%s"' % nodeAddr
      sys.exit(1)
  for i in data:
    line = []
    for j in fields:
      if j[0] is 't':
        line.append(j[1])
      elif j[0] is 'f':
        if j[1] in i.keys():
          if isinstance(i[j[1]], unicode):
            hay = i[j[1]].replace('\t', ' ')
          elif isinstance(i[j[1]], (int, float)):
            hay = str(i[j[1]])
          elif isinstance(i[j[1]], NoneType):
            hay = 'NULL'
          else:
            hay = i[j[1]]
          line.append(hay)
        else:
          print 'Err: unable to find a field "%s"' % j
          sys.exit(1)
    print u'\t'.join(line).encode('utf-8')
  sys.exit()

if __name__ == "__main__":
   main(sys.argv)