How to put items into priority queues?

Just use the second item of the tuple as a secondary priority if a alphanumeric sort on your string data isn't appropriate. A date/time priority would give you a priority queue that falls back to a FIFIO queue when you have multiple items with the same priority. Here's some example code with just a secondary numeric priority. Using a datetime value in the second position is a pretty trivial change, but feel free to poke me in comments if you're not able to get it working.

Code

import Queue as queueprio_queue = queue.PriorityQueue()prio_queue.put((2, 8, 'super blah'))prio_queue.put((1, 4, 'Some thing'))prio_queue.put((1, 3, 'This thing would come after Some Thing if we sorted by this text entry'))prio_queue.put((5, 1, 'blah'))while not prio_queue.empty():    item = prio_queue.get()    print('%s.%s - %s' % item)

Output

1.3 - This thing would come after Some Thing if we didn't add a secondary priority1.4 - Some thing2.8 - super blah5.1 - blah

Edit

Here's what it looks like if you use a timestamp to fake FIFO as a secondary priority using a date. I say fake because it's only approximately FIFO as entries that are added very close in time to one another may not come out exactly FIFO. I added a short sleep so this simple example works out in a reasonable way. Hopefully this helps as another example of how you might get the ordering you're after.

import Queue as queueimport timeprio_queue = queue.PriorityQueue()prio_queue.put((2, time.time(), 'super blah'))time.sleep(0.1)prio_queue.put((1, time.time(), 'This thing would come after Some Thing if we sorted by this text entry'))time.sleep(0.1)prio_queue.put((1, time.time(), 'Some thing'))time.sleep(0.1)prio_queue.put((5, time.time(), 'blah'))while not prio_queue.empty():    item = prio_queue.get()    print('%s.%s - %s' % item)

As far as I know, what you're looking for isn't available out of the box. Anyway, note that it wouldn't be hard to implement:

from Queue import PriorityQueueclass MyPriorityQueue(PriorityQueue):    def __init__(self):        PriorityQueue.__init__(self)        self.counter = 0    def put(self, item, priority):        PriorityQueue.put(self, (priority, self.counter, item))        self.counter += 1    def get(self, *args, **kwargs):        _, _, item = PriorityQueue.get(self, *args, **kwargs)        return itemqueue = MyPriorityQueue()queue.put('item2', 1)queue.put('item1', 1)print queue.get()print queue.get()

Example output:

item2item1

I made something like this to accomplish a FIFO similar to gfortune, but without the need of calling time.time() everywhere: (Python 3 only)

import timefrom dataclasses import dataclass, field@dataclass(order=True)class PrioritizedItem:    prio: int    timestamp: float = field(init=False, default_factory=time.time)    data: object = field(compare=False)

Now you can do:

import queueitem1 = PrioritizedItem(0, "hello world")item2 = PrioritizedItem(0, "what ever")q = queue.PriorityQueue()q.put(item1)q.put(item2)

And be sure, they will always be extracted in the same order.