shorten 0.2.0

A Python library for generating short URLs.

A Python library for generating short URLs.

It’s gevent-safe, so you can use it with Gunicorn (and consequently Flask, Django and Pyramid).

Installation

Install with pip: pip install shorten

If you want to run the tests, ensure nose is installed with pip install nose.

The basics

Make a shortener:

import shorten
import redis

shortener = shorten.shortener('redis', redis=redis.Redis())

Map a short key to a long value:

# '2111'
key = shortener.insert('http://mitpress.mit.edu/sicp/full-text/book/book.html')

Map multiple keys and values from greenlets:

import gevent

values = [
  'aardvark',
  'bonobo',
  'caiman',
  'degu',
  'elk',
]

jobs = [gevent.spawn(shortener.insert, v) for v in values]
keys = map(lambda j: j.value, gevent.joinall(jobs, timeout=2))

# ['2111', '2112', '2114', '2113', '2115']
print(keys)

If you wish to store the keys with some sort of prefix, pass in a formatter function when a KeyStore is created:

import shorten
import redis

def to_key_format(token):
  return 'my:namespace:key:{0}'.format(token)

shortener = shorten.shortener('redis', redis=redis.Redis(), formatter=to_key_format)

# 'my:namespace:key:2111'
key = shortener.insert('http://mitpress.mit.edu/sicp/full-text/book/book.html')

Custom alphabets of symbols (any 0-index based iterable) can be passed to the shortener function too:

import shorten

# Use an alternative alphabet with faces
alphabet = [
  ':)', ':(', ';)', ';(', '>:)', ':D', ':x', ':X', ':|', ':O', '><', '<<', '>>', '^^', 'O_o', u'?_?',
]

shortener = shorten.shortener('memory', alphabet=alphabet)

values = [
  'aardvark',
  'bonobo',
  'caiman',
  'degu',
  'elk',
]

keys = map(shortener.insert, values)

# [':(:):):)', ':(:):):(', ':(:):);)', ':(:):);(', ':(:):)>:)']
print(keys)

Example

For a more real-world example, here’s a URL-shortening website that accepts URLs and returns the shortened key via JSON.

# For example, run as:
# gunicorn -w 4 example:app

import re
from redis import Redis
from flask import Flask, request, redirect, url_for, jsonify
from werkzeug import iri_to_uri
from shorten import shortener

app = Flask(__name__)
app_name = 'short.ur'

redis = Redis()

def is_url(string):
   return re.match('http(s){0,1}://.+\..+', string, re.I) is not None

def to_short_token(key):
   return key.split(to_short_key(''), 1)[1]

def to_short_key(token):
   return '{0}:key:{1}'.format(app_name, token)

counter_key = '{0}:counter'.format(app_name)

shortener = shortener('redis', redis=redis,
                              counter_key=counter_key,
                              formatter=to_short_key)

@app.route('/')
def shorten():
   try:
      url = request.args['u'].strip()
      if not is_url(url):
         return jsonify({'error' : 'not a valid url'})
      else:
         token = to_short_token(shortener.insert(url))
         return jsonify({'short' : url_for('bounce', token=token)})
   except KeyError, e:
      return jsonify({'error' : 'no url to shorten'})

@app.route('/<token>')
def bounce(token):
   try:
      token = to_short_key(token)
      return redirect(iri_to_uri(shortener[token]))
   except KeyError:
      return jsonify({'error' : 'no short url found'})

if __name__ == '__main__':
   app.run('0.0.0.0')