Python JSON Prettifier by Sujit Pal, from http://sujitpal.blogspot.com/2011/05/python-json-prettifier.html

jsoncat.py

#!/usr/bin/python
# -*- coding: utf-8 -*-
#
# Converts the specified JSON file with the specified encoding
# (default encoding is utf8 if not specified) into a formatted 
# version with the specified indent (2 if not specified) and 
# writes to STDOUT.
#
# Usage: jsoncat.py inputfile.json [input_encoding] [indent]
#
import sys
import json
import codecs

def usage():
  print "Usage: %s input.json [input_encoding] [indent]" % sys.argv[0]
  print "input.json - the input file to read"
  print "input_encoding - optional, default utf-8"
  print "indent - optional, default 2"
  sys.exit(-1)

def prettyPrint(obj, indent, depth, suffix=False):
  if isinstance(obj, list):
    sys.stdout.write("%s[\n" % str(" " * indent * depth))
    sz = len(obj)
    i = 1
    for row in obj:
      prettyPrint(row, indent, depth + 1, i < sz)
      i = i + 1
    ct = "," if suffix else ""
    sys.stdout.write("%s]%s\n" % (str(" " * indent * depth), ct))
  elif isinstance(obj, dict):
    sys.stdout.write("%s{\n" % str(" " * indent * depth))
    sz = len(obj.keys())
    i = 1
    for key in obj.keys():
      sys.stdout.write("%s%s :" % (str(" " * indent * (depth + 1)), qq(key)))
      val = obj[key]
      if isinstance(val, list) or isinstance(val, dict):
        prettyPrint(val, indent, depth + 1, i < sz)
      else:
        prettyPrint(val, 1, 1, i < sz)
      i = i + 1
    ct = "," if suffix else ""
    sys.stdout.write("%s}%s\n" % (str(" " * indent * depth), ct))
  else:
    ct = "," if suffix else ""
    sys.stdout.write("%s%s%s\n" % (str(" " * indent * depth), qq(obj), ct))

def qq(obj):
  if isinstance(obj, unicode):
    return "\"" + obj.encode('ascii', 'xmlcharrefreplace') + "\""
  else:
    return repr(obj)

def main():
  if len(sys.argv) < 2 and len(sys.argv) > 4:
    usage()
  encoding = "utf-8" if len(sys.argv) == 2 else sys.argv[2]
  indent = 2 if len(sys.argv) == 3 else sys.argv[3]
  infile = codecs.open(sys.argv[1], "r", encoding)
  content = infile.read()
  infile.close()
  jsobj = json.loads(content)
  prettyPrint(jsobj, indent, 0)
  
if __name__ == "__main__":
  main()