Tiny library/command-line-program for converting between json and plist formats. I use it for editing SublimeText setting files.

jsonplist.py

#!/usr/bin/python
# -*- coding: utf-8 -*-

import plistlib
import json
import StringIO

# Takes as input a string of either JSON or Plist.
# Returns the opposite, assuming no errors.
def convert(input):
    try:
        inputType = "json"
        data = json.loads(input)
    except Exception, e:
        try:
            inputType = "plist"
            data = plistlib.readPlist(StringIO.StringIO(input))
        except:
            print("FATAL ERROR: Couldn't parse input as either JSON or Plist.")
            raise

    if inputType == "json":
        output = StringIO.StringIO()
        plistlib.writePlist(data, output)
        return output.getvalue()
    return json.dumps(data, indent=2)

if __name__ == "__main__":
    import optparse
    import sys
    optparser = optparse.OptionParser("usage: %prog [options] inputFile")
    optparser.add_option("-i", "--in", dest="inputFile",
                         help="Path to the source file. [default: standard input]")
    optparser.add_option("-o", "--out", dest="outputFile",
                         help="Path to the output file. [default: standard output]")
    optparser.add_option("-r", "--replace", dest="replace", action="store_true",
                         help="Just replaces the input file with the output. Must specify an input as well.")
    (options, posargs) = optparser.parse_args()

    if len(posargs) == 1:
        options.inputFile = posargs[0]
    elif len(posargs) == 0:
        inputFile = None
    else:
        optparser.error("One or zero arguments, please.")

    if options.inputFile and options.replace:
        options.outputFile = options.inputFile

    if options.inputFile:
        with open(options.inputFile, 'r') as input:
            output = convert(input.read())
    else:
        input = sys.stdin.read()
        output = convert(input)

    if options.outputFile:
        with open(options.outputFile, 'w') as outputF:
            outputF.write(output)
    else:
        print(output)