抽象的 Django 模型管理器

Question

我在这里缺乏Python元编程知识。假设我有以下内容：

class OwnCompanyManager(models.Manager):
    """Only companies of this user"""
    def get_queryset(self, user):
        if user.is_superuser:
            return super(OwnCompanyManager, self).get_queryset()
        return super(OwnCompanyManager, self).get_queryset().filter(
            companyuser__user=user)

class OwnPublisherManager(models.Manager):
    """Only publishers of this user's company"""
    def get_queryset(self, user):
        if user.is_superuser:
            return super(OwnPublisherManager, self).get_queryset()
        return super(OwnPublisherManager, self).get_queryset().filter(
            company__companyuser__user=user)
class Company(models.Model):
    name = models.CharField(max_length=45)
    objects = models.Manager()
    own = OwnCompanyManager()

class Publisher(models.Model):
    company = models.ForeignKey(Company)
    allow_latest_dev = models.BooleanField(default=False)
    domains_blocked = models.BooleanField(default=False)
    objects = models.Manager()
    own = OwnPublisherManager()

我还有很多。我不喜欢复制粘贴样板Own(Publisher|Company|Etcetra)Manager).如您所见，唯一的变化是在过滤器中。

如何从Company、Publisher和其他模型中抽象Own(InsertModelNameHere)Manager并使用它？我想在管理器定义中指定过滤器 kwargs。

Answer 1

这里不需要元编程或任何特别聪明的东西。您只需要提取更改的位。在这种情况下，它只是要filter的参数：您可以使用参数传递的字典形式，并将过滤器作为字符串存储在类属性中。

class AbstractManager(models.Manager):
    def get_queryset(self, user):
        if user.is_superuser:
            return super(AbstractManager, self).get_queryset()
        return super(AbstractManager, self).get_queryset().filter(**{self.filter: user})
class OwnCompanyManager(AbstractManager):
    filter = "companyuser__user"
class OwnPublisherManager(AbstractManager):
    filter = "company__companyuser__user"

Answer 2

灵感来自丹尼尔的回复：

class OwnManager(models.Manager):
    def __init__(self, key):
        super(OwnManager, self).__init__()
        self.k = key
    def get_queryset(self, user):
        if user.is_superuser:
            return super(OwnManager, self).get_queryset()
        return super(OwnManager, self).get_queryset().filter(**{self.k: user})

class Company(models.Model):
    name = models.CharField(max_length=45)
    objects = models.Manager()
    own = OwnManager("companyuser__user")

class Publisher(models.Model):
    company = models.ForeignKey(Company)
    allow_latest_dev = models.BooleanField(default=False)
    domains_blocked = models.BooleanField(default=False)
    objects = models.Manager()
    own = OwnManager("company__companyuser__user")

这样我就不想为每个模型创建愚蠢的类。

谢谢丹尼尔。