Django检查ManyToMany字段中是否有对象 [英] Django check if object in ManyToMany field

问题描述

我有一个很简单的问题要解决.我有合作伙伴模型，其中有 >= 0 个与之关联的用户:

I have quite a simple problem to solve. I have Partner model which has >= 0 Users associated with it:

class Partner(models.Model):
    name = models.CharField(db_index=True, max_length=255)
    slug = models.SlugField(db_index=True)
    user = models.ManyToManyField(User)

现在，如果我有一个 User 对象和一个 Partner 对象，那么检查用户是否与合作伙伴关联的最 Pythonic 的方法是什么?如果 User 与 Partner 相关联，我基本上想要一个返回 True 的语句.

Now, if I have a User object and I have a Partner object, what is the most Pythonic way of checking if the User is associated with a Partner? I basically want a statement which returns True if the User is associated to the Partner.

我试过了:

users = Partner.objects.values_list('user', flat=True).filter(slug=requested_slug)
if request.user.pk in users:
    # do some private stuff

这可行，但我觉得有更好的方法.此外，这是否容易融入装饰器，记住我需要一个命名参数(slug)和一个请求对象(user).

This works but I have a feeling there is a better way. Additionally, would this be easy to roll into a decorator, baring in mind I need both a named parameter (slug) and a request object (user).

推荐答案

if user.partner_set.filter(slug=requested_slug).exists():
     # do some private stuff

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