How to iterate through a Python Queue.Queue with a for loop instead of a while loop?

You can use iter with callable. (You should pass two arguments, one for the callable, the other for the sentinel value)

for job in iter(queue.get, None): # Replace `None` as you need.
    # do stuff with job

NOTE This will block when no elements remain and no sentinel value is put. Also, like a while-get loop and unlike normal for loops over containers, it will remove items from the queue.

UPDATE: None is common value, so here's a sample with more concrete sentinel value:

sentinel = object()
for job in iter(queue.get, sentinel):
    # do stuff with job

For that kind of queue actually I would not typically use this check of queue.empty() because I always use it in a threaded context and thus cannot know whether another thread would put something in there in a few milliseconds (thus that check would be useless anyway). I never check a queue for being empty. I rather use a sentinel value which marks the ending of a producer.

So using the iter(queue.get, Sentinel) is more what I like.

If you know that no other thread will put items in the queue anymore and just want to drain it from all currently contained items, then you can use sth like this:

class Drainer(object):
  def __init__(self, q):
    self.q = q
  def __iter__(self):
    while True:
      try:
        yield self.q.get_nowait()
      except queue.Empty:  # on python 2 use Queue.Empty
        break

for item in Drainer(q):
  print(item)

or

def drain(q):
  while True:
    try:
      yield q.get_nowait()
    except queue.Empty:  # on python 2 use Queue.Empty
      break

for item in drain(q):
  print(item)

I would say this is an easy way to iterate over queue in some points:

from queue import Queue

q = Queue()
q.put(1)
q.put(2)
q.put(3)

for i in q.queue:
    print(i)