old_contents: import os
  import urlparse
  from redis import Redis
  from rq import Worker, Queue, Connection
  
  listen = ['high', 'default', 'low']
  
  redis_url = (os.getenv('REDISTOGO_URL') or 'http://localhost:6379')
  urlparse.uses_netloc.append('redis')
  url = urlparse.urlparse(redis_url)
  conn = Redis(host=url.hostname, port=url.port, db=0, password=url.password)
  
  with Connection(conn):
  	worker = Worker(map(Queue, listen))
  	worker.work()
  
new_contents: import os
  import urlparse
  from redis import Redis
  from rq import Worker, Queue, Connection
  
  listen = ['high', 'default', 'low']
  
  redis_url = os.getenv('REDISTOGO_URL', 'http://localhost:6379')
  urlparse.uses_netloc.append('redis')
  url = urlparse.urlparse(redis_url)
  conn = Redis(host=url.hostname, port=url.port, db=0, password=url.password)
  
  with Connection(conn):
  	worker = Worker(map(Queue, listen))
  	worker.work()
  
subject: Use getenv built-in default selection