芹菜任务将结果返回给父任务

Question

>我有一个芹菜网页抓取任务，我想将所有创建的子对象返回给父对象。如何将这些 ID 取回给父级？

我正在尝试做的粗略示例

@task
def scrape_page(url):
    page = Page.objects.create(
        name='new_page'
    )
    response = requests.get(url)
    children = parse_children(response)
    for child in children:
        result = scrape_child.delay(child.url)
        page.childen.add(result)
@task
def scrape_child(url):
    response = requests.get(url)
    parsed = parse_child(response)
    child = Child.objects.create(**parsed)
    return child

Answer 1

您不应该等待任务中的延迟任务，您可以与.apply()同步调用该任务，但这不会调用单独的任务。编辑：我找到了文档，请参阅避免启动同步子任务

也许你应该使用组。一种方法是延迟一组scrape_child任务并发送父任务page_id

from celery import group
@task
def scrape_page(url):
    page = Page.objects.create(
        name='new_page'
    )
    response = requests.get(url)
    children = parse_children(response)
    children_group = group([
        scrape_child.s(page.id, child.url)  # using the signature
        for child in children
    ])
    children_group.delay()
    return True
@task
def scrape_child(page_id, url):
    response = requests.get(url)
    parsed = parse_child(response)
    child = Child.objects.create(**parsed)
    child.page_id = page_id
    return child