1/18/2024 0 Comments Key for python priority queue![]() Because it is technicallyĪn import _name_ = '_main_' will not work. Execute a python file: dot-separated pathname of the file.Execute a function: dot-separated string of package, module and function (Just like.-schedule-at Schedule job to be enqueued at a certain time formatted.-schedule-in Delay until the function is enqueued (e.g.-retry-interval Interval between retries in seconds.-at-front Will place the job at the front of the queue, instead.-depends-on Specifies another job id that must complete before this.-description Additional description of the job.-failure-ttl Specifies how long failed jobs are kept.-ttl Specifies the maximum queued time of the job before.-result-ttl Specifies how long successful jobs and their results.-timeout Specifies the maximum runtime of the job before it is.To your job and not to RQ’s enqueue function, this is what you do: In the last case, if you want to pass description and ttl keyword arguments This is useful if your function happens to haveĬonflicting argument names with RQ, for example description or ttl. args and kwargs: use these to explicitly pass arguments and keyword to the.on_stopped allows you to run a function after a job is stopped.on_failure allows you to run a function after a job fails.on_success allows you to run a function after a job completes successfully.description to add additional description to enqueued jobs. ![]() at_front will place the job at the front of the queue, instead of the.job_id allows you to manually specify this job’s job_id.depends_on specifies another job (or list of jobs) that must complete before this.failure_ttl specifies how long failed jobs are kept (defaults to 1 year).This argument defaults to None (infinite TTL). ttl specifies the maximum queued time (in seconds) of the job before it’s discarded.Expired jobs will be automatically deleted. result_ttl specifies how long (in seconds) successful jobs and their.Furthermore, it can be a string with specify unit including hour, minute, second(e.g. Its default unit is second and it can be an integer or a string representing an integer(e.g. job_timeout specifies the maximum runtime of the job before it’s interruptedĪnd marked as failed. ![]() By default, these are popped out of the kwargs that will be passed to the In addition, you can add a few options to modify the behaviour of the queued Pattern is to name your queues after priorities (e.g. You can quite flexibly distribute work to your own desire. Notice the Queue('low') in the example above? You can use any queue name, so One simple approach if you hit this problem is following a suggestion in the heapq documentation: “store entries as 3-element list including the priority, an entry count, and the task”, where the entry count is a tie-breaker for jobs of equal priority.Q = Queue ( 'low', connection = redis_conn ) q. For the application I was working on, I needed to retrieve items based on priority, and for items of equal priority, I needed to retrieve items in FIFO order. Here’s an approach I used for Python 3.5 (the version of Python I was writing for when I looked into using this functionality). ![]() 'Another job' will bubble to the top of the heap since 'Another job' < 'My first job'. In Python, this is done using the rich comparison operator _lt_. So to get the next job we want to run, we just grab the element at the top of the min-heap, which due to the min-heap property, we know will be the job with the minimum priority value - which remember from above corresponds to the higher priority.īut where is this comparison done: 'Another job' < 'My first job'? During heap operations, elements are compared with one another (and swapped if needed). The root element will be the node with the minimum value. A min-heap is a complete binary tree that satisfies the min-heap propety: the value of each node is greater than or equal to the value of its parent. The longer version is that under the hood, queue.PriorityQueue is implemented using heapq, Python’s heap implementation. The short version is that we grabbed 'Another job' first, because 'Another job' < 'My first job' alphabetically. Why does this happen? Using a min-heap for queue.PriorityQueue We did not retrieve items in FIFO order for jobs of equal priority: 'Another job' was fetched prior to 'My first job' even though it was added afterwards.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |