I’m new to programming in python, and I have a task to try and create continuous Queue but with Delay support. I haven’t added the threading or sharing the data q across threads yet but I still need the functionality for managing the delay.

With the examples I’ve seen using the queue class directly, it seems like I should be able to create a much more compact class than what I have written, but I wanted to see if someone could help pare this down to a more optimal class for managing. What I have here works, but hoping to be a bit more pythonic.

I’d really love it if someone could point out areas where I could be more efficient.

Here’s what I wrote so far:

import multiprocessing, requests import copy import time import pprint from enum import Enum from queue import Queue  from datetime import datetime, timedelta from multiprocessing import Pool  class QueueState(Enum):     Inactive = 0     Sleeping = 1     Processing = 2  class DelayQueue:      def __init__(self):         self.state = QueueState.Inactive         self.queue = []      def run(self):         while True:             currentwork = [item for item in self.queue if item.time <= datetime.now()]             currentwork.sort(key=lambda x: x.time, reverse=False)              print(len(currentwork), 'tasks ready for processing')             #Process the currentwork             for i, task in list(enumerate(currentwork)):                 if i == 0:                     print('Processing currentwork')                  print('Processing item', i)                 if task.process() == True:                     currentwork.remove(task)                     self.queue.remove(task)              print('Processing current tasks complete')             #No work ready yet             if len(currentwork) == 0 and len(self.queue) > 0:                 print("No work ready to process")              if len(self.queue) == 0:                 print('Queue empty closing queue')                 self.state = QueueState.Inactive                 break             elif len(currentwork) == 0:                 self.queue.sort(key=lambda x: x.time, reverse=False)                 nexttask = self.queue[0]                 print("Getting next task", nexttask)                 delta =  nexttask.time - datetime.now()                 print('Sleeping', delta.total_seconds(), 'seconds')                 self.state = QueueState.Sleeping                 if delta.total_seconds() > 0:                     time.sleep(delta.total_seconds())      def add(self, func, delay=0, **kwargs):         self.queue.append(Task(func, datetime.now() + timedelta(milliseconds=delay), **kwargs))         #if self.state == QueueState.Inactive:         #self.run()      def remove():         raise NotImplementedError  class Task:     def __init__(self, func, time, **kwargs):         print("New task", (func.__name__, time, kwargs))         self.func = func         self.time = time         self.args = kwargs      def process(self):         self.func(**self.args)         return True     def __str__(self):         return str((self.func.__name__, self.time, self.args))  def get(**kwargs):     url = kwargs['url']     print('Requesting', url)     r = requests.get(url=url)     print("Status Code", r.status_code)   queue = DelayQueue()  queue.add(get, 1500, url='http://www.google.com') queue.add(get, 4300, url='http://www.yahoo.com') queue.add(get, 3900, url='http://www.att.com') queue.add(get, 2500, url='http://www.nbc.com') queue.add(get, 2450, url='http://www.msn.com') queue.add(get, 2450, url='http://www.gmail.com')  queue.run() 

Output:

New task ('get', datetime.datetime(2018, 1, 19, 17, 18, 51, 843225), {'url': 'http://www.google.com'}) New task ('get', datetime.datetime(2018, 1, 19, 17, 18, 54, 643616), {'url': 'http://www.yahoo.com'}) New task ('get', datetime.datetime(2018, 1, 19, 17, 18, 54, 243917), {'url': 'http://www.att.com'}) New task ('get', datetime.datetime(2018, 1, 19, 17, 18, 52, 844260), {'url': 'http://www.nbc.com'}) New task ('get', datetime.datetime(2018, 1, 19, 17, 18, 52, 794472), {'url': 'http://www.msn.com'}) New task ('get', datetime.datetime(2018, 1, 19, 17, 18, 52, 794630), {'url': 'http://www.gmail.com'}) 0 tasks ready for processing Processing current tasks complete No work ready to process Getting next task ('get', datetime.datetime(2018, 1, 19, 17, 18, 51, 843225), {'url': 'http://www.google.com'}) Sleeping 1.498037 seconds 1 tasks ready for processing Processing currentwork Processing item 0 Requesting http://www.google.com Status Code 200 Processing current tasks complete No work ready to process Getting next task ('get', datetime.datetime(2018, 1, 19, 17, 18, 52, 794472), {'url': 'http://www.msn.com'}) Sleeping 0.820134 seconds 2 tasks ready for processing Processing currentwork Processing item 0 Requesting http://www.msn.com Status Code 200 Processing item 1 Requesting http://www.gmail.com Status Code 200 Processing current tasks complete No work ready to process Getting next task ('get', datetime.datetime(2018, 1, 19, 17, 18, 52, 844260), {'url': 'http://www.nbc.com'}) Sleeping -0.540612 seconds 1 tasks ready for processing Processing currentwork Processing item 0 Requesting http://www.nbc.com Status Code 200 Processing current tasks complete No work ready to process Getting next task ('get', datetime.datetime(2018, 1, 19, 17, 18, 54, 243917), {'url': 'http://www.att.com'}) Sleeping 0.708722 seconds 1 tasks ready for processing Processing currentwork Processing item 0 Requesting http://www.att.com Status Code 200 Processing current tasks complete No work ready to process Getting next task ('get', datetime.datetime(2018, 1, 19, 17, 18, 54, 643616), {'url': 'http://www.yahoo.com'}) Sleeping 0.143595 seconds 1 tasks ready for processing Processing currentwork Processing item 0 Requesting http://www.yahoo.com Status Code 200 Processing current tasks complete Queue empty closing queue