在遍历http请求之后，如何使用python多处理获得全局和？

Question

我试图编写一个算法，遍历整个节点集合并返回它们的奖励总和。每个奖励只应计算一次。算法的输入将是节点开始时的URL，例如http://fake.url/a

URL的每个get请求都将返回一个JSON，如下所示：

{
      "children":[
        "http://fake.url/b",
        "http://fake.url/c"
      ],
      "reward":1
    }

以下是我尝试过的：

import multiprocessing
import requests
import json

my_q = multiprocessing.Queue()
my_list  =['http://fake.url/']
reward_sum = 0

def enqueue(q):
    for data in my_list:
        q.put(data)

def get_it(q):
    while not q.empty():
        item = q.get()
        print(item)
        response = requests.get(item)
        kids = json.loads(response.content)
        print(f'URL: {item} --> {kids["reward"]}')
        for kid in kids['children']:
            print(kid)
            q.put(kid)

p1 = multiprocessing.Process(target=enqueue, args=(my_q,))
p2 = multiprocessing.Process(target=get_it, args=(my_q,))
p1.start()
p2.start()

p1.join()
p2.join()

以上工作原理：

1. 我正在使用多重处理
2. 我正在正确访问孩子和奖励
3. 我得到如下输出：

    http://fake.url/a
    URL: http://fake.url/a --> 1
    {'children': ['http://fake.url/b', 'http://fake.url/c'], 'reward': 1}
    http://fake.url/b
    http://fake.url/c
    http://fake.url/b
    URL: http://fake.url/b --> 2
    {'children': ['http://fake.url/d', 'http://fake.url/e'], 'reward': 2}
    http://fake.url/d
    http://fake.url/e
    http://fake.url/c
    URL: http://fake.url/c --> 3
    {'children': ['http://fake.url/f', 'http://fake.url/g'], 'reward': 3}
    http://fake.url/f
    http://fake.url/g
    http://fake.url/d
    URL: http://fake.url/d --> 4
    {'reward': 4}
    http://fake.url/e
    URL: http://fake.url/e --> 5
    {'reward': 5}
    http://fake.url/f
    URL: http://fake.url/f --> 6
    {'children': ['http://fake.url/h'], 'reward': 6}
    http://fake.url/h
    http://fake.url/g

我需要帮助解决哪些问题：

1. 如何在全局变量中跟踪奖励总额
2. 如何跟踪全局“看到”集，这样我就不会将重复项添加到总奖励金额中

Answer 1

def get_it(q):
    rewards_total = 0
    seen = set()
    while not q.empty():
        item = q.get()
        print(item)
        if item in seen:
            continue
        seen.add(item)
        response = requests.get(item)
        kids = json.loads(response.content)
        rewards_total += kids["reward"]
        print(f'URL: {item}  > {kids["reward"]}')
        for kid in kids['children']:
            print(kid)
            q.put(kid)
    return rewards_total