Compiles javascript to bookmarklet

compile.py

import sys
import json
import urllib
import argparse

def request_compile(code):
    url = 'http://closure-compiler.appspot.com/compile'

    # Encode data
    params = urllib.urlencode([
       ('js_code', code),
       ('compilation_level', 'WHITESPACE_ONLY'),
       ('output_format', 'json'),
       ('output_info', 'compiled_code'),
       ('output_info', 'warnings'),
       ('output_info', 'errors'),
    ])

    # Send request
    data = urllib.urlopen(url, params).read()

    data = json.loads(data)
    return data

def bookmarkletify(code):
    code = code.replace(' ', '%20')
    return 'javascript:' + code

def print_error(e):
    charno = e['charno']
    print >> sys.stderr, 'Error      :', e['error']
    print >> sys.stderr, 'Error Type :', e['type']
    print >> sys.stderr, 'Line No    :', e['lineno']
    print >> sys.stderr, 'Char No    :', charno
    print >> sys.stderr, 'File       :', e['file']
    print >> sys.stderr, 'Line       :', e['line']
    print >> sys.stderr, '            ', (' ' * charno) + '^'

def print_warning(w):
    print >> sys.stderr, 'Warning   :', w['warning']
    print >> sys.stderr, 'Warn Type :', w['type']
    print >> sys.stderr, 'Line No   :', w['lineno']
    print >> sys.stderr, 'Char No   :', w['charno']
    print >> sys.stderr, 'File      :', w['file']
    print >> sys.stderr, 'Line      :', w['line']

def main():
    parser = argparse.ArgumentParser(prog='COMPILE')
    parser.add_argument('source', metavar='SOURCE', type=str, nargs=1,
        help='source file name that will be compiled')
    parser.add_argument('dest', metavar='DEST', type=str, nargs=1,
        help='destination file name that will save compiled source')
    args = parser.parse_args()
    source = args.source[0]
    dest = args.dest[0]

    with open(source) as f:
        code = f.read()

    data = request_compile(code)
    warnings = data.get('warnings', [])
    errors = data.get('errors', [])

    for w in warnings:
        WARNING = 'WANRNING'
        cnt = 80 - len(WARNING) - 2
        print ('=' * (cnt//2)) + ' ' + WARNING + ' ' + ('=' * (cnt//2))
        print_warning(w)

    for e in errors:
        ERROR = 'ERROR'
        cnt = 80 - len(ERROR) - 2
        print ('=' * (cnt//2)) + ' ' + ERROR +' ' + ('=' * ((cnt//2) + 1))
        print_error(e)

    print '%d error(s), %d warning(s)' % (len(errors), len(warnings))

    if len(errors) == 0:
        code = data['compiledCode']

        with open(dest, 'w') as f:
            f.write(bookmarkletify(code))

        print 'Compression Finished!'

if __name__ == '__main__':
    main()