Parallel HTTP requests in Python

Edit: thankfully this is now outdated! See Parallel asynchronous GET requests with asyncio instead

• I've come across this in Go and thought it looked hairy, but the solution in Python seems simple (and old news even!)

• Will Larson's 2008 blog post shares the following (which I've Py3-ified and replaced urllib with requests):

  from threading import Thread, enumerate
  from requests import get
  from time import sleep
  from functools import reduce
  
  UPDATE_INTERVAL = 0.01
  
  class URLThread(Thread):
      def __init__(self, url):
          super(URLThread, self).__init__()
          self.url = url
          self.response = None
  
      def run(self):
          self.response = get(self.url)
  
  def multi_get(uris, timeout=2.0):
      def alive_count(lst):
          alive = map(lambda x: 1 if x.isAlive() else 0, lst)
          return reduce(lambda a,b: a+b, alive)
      threads = [URLThread(uri) for uri in uris]
      for thread in threads:
          thread.start()
      while alive_count(threads) > 0 and timeout > 0.0:
          timeout = timeout - UPDATE_INTERVAL
          sleep(UPDATE_INTERVAL)
      return [(x.url, x.response) for x in threads]

• simply execute this function and it will return an array of (url, payload) tuples corresponding to the input sites array order once the last request is returned