urlshort.py

import itertools
import sys
from bottle import route, run, redirect

ALPHANUM = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789'

def usage():
    print 'usage: %s <hostname> <port>'
    exit(-1)

if len(sys.argv) != 3:
    usage()

hostname = sys.argv[1]
port = int(sys.argv[2])
urls = {}

@route('/')
def index():
    return 'Nothing here.'

def codes():
    for size in range(1, 4):
        for p in itertools.permutations(list(ALPHANUM), size):
            yield ''.join(p)
codes = codes()

@route('/get/:url')
def shorten(url):
    code = codes.next()
    urls[code] = url
    return 'Your short url: %s/%s' % (hostname, code)

@route('/:code')
def find(code):
    if code not in urls:
        return 'Go away.'
    url = 'http://' + urls[code]
    redirect(url)

run(host=hostname, port=port)