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	Black 23.1.0 is released which, as the first release of the year, introduces the 2023 stable style. This incorporates most of last year's preview style. https://github.com/psf/black/releases/tag/23.1.0
		
			
				
	
	
		
			184 lines
		
	
	
		
			5.4 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			184 lines
		
	
	
		
			5.4 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
| from django.contrib.contenttypes.fields import GenericForeignKey, GenericRelation
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| from django.contrib.contenttypes.models import ContentType
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| from django.db import models
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| 
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| 
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| class Relation(models.Model):
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|     pass
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| 
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| 
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| class InstanceOnlyDescriptor:
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|     def __get__(self, instance, cls=None):
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|         if instance is None:
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|             raise AttributeError("Instance only")
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|         return 1
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| 
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| 
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| class AbstractPerson(models.Model):
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|     # DATA fields
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|     data_abstract = models.CharField(max_length=10)
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|     fk_abstract = models.ForeignKey(
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|         Relation, models.CASCADE, related_name="fk_abstract_rel"
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|     )
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| 
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|     # M2M fields
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|     m2m_abstract = models.ManyToManyField(Relation, related_name="m2m_abstract_rel")
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|     friends_abstract = models.ManyToManyField("self", symmetrical=True)
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|     following_abstract = models.ManyToManyField(
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|         "self", related_name="followers_abstract", symmetrical=False
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|     )
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| 
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|     # VIRTUAL fields
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|     data_not_concrete_abstract = models.ForeignObject(
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|         Relation,
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|         on_delete=models.CASCADE,
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|         from_fields=["abstract_non_concrete_id"],
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|         to_fields=["id"],
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|         related_name="fo_abstract_rel",
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|     )
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| 
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|     # GFK fields
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|     content_type_abstract = models.ForeignKey(
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|         ContentType, models.CASCADE, related_name="+"
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|     )
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|     object_id_abstract = models.PositiveIntegerField()
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|     content_object_abstract = GenericForeignKey(
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|         "content_type_abstract", "object_id_abstract"
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|     )
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| 
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|     # GR fields
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|     generic_relation_abstract = GenericRelation(Relation)
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| 
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|     class Meta:
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|         abstract = True
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| 
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|     @property
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|     def test_property(self):
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|         return 1
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| 
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|     test_instance_only_descriptor = InstanceOnlyDescriptor()
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| 
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| 
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| class BasePerson(AbstractPerson):
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|     # DATA fields
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|     data_base = models.CharField(max_length=10)
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|     fk_base = models.ForeignKey(Relation, models.CASCADE, related_name="fk_base_rel")
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| 
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|     # M2M fields
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|     m2m_base = models.ManyToManyField(Relation, related_name="m2m_base_rel")
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|     friends_base = models.ManyToManyField("self", symmetrical=True)
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|     following_base = models.ManyToManyField(
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|         "self", related_name="followers_base", symmetrical=False
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|     )
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| 
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|     # VIRTUAL fields
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|     data_not_concrete_base = models.ForeignObject(
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|         Relation,
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|         on_delete=models.CASCADE,
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|         from_fields=["base_non_concrete_id"],
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|         to_fields=["id"],
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|         related_name="fo_base_rel",
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|     )
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| 
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|     # GFK fields
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|     content_type_base = models.ForeignKey(ContentType, models.CASCADE, related_name="+")
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|     object_id_base = models.PositiveIntegerField()
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|     content_object_base = GenericForeignKey("content_type_base", "object_id_base")
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| 
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|     # GR fields
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|     generic_relation_base = GenericRelation(Relation)
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| 
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| 
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| class Person(BasePerson):
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|     # DATA fields
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|     data_inherited = models.CharField(max_length=10)
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|     fk_inherited = models.ForeignKey(
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|         Relation, models.CASCADE, related_name="fk_concrete_rel"
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|     )
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| 
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|     # M2M Fields
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|     m2m_inherited = models.ManyToManyField(Relation, related_name="m2m_concrete_rel")
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|     friends_inherited = models.ManyToManyField("self", symmetrical=True)
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|     following_inherited = models.ManyToManyField(
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|         "self", related_name="followers_concrete", symmetrical=False
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|     )
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| 
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|     # VIRTUAL fields
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|     data_not_concrete_inherited = models.ForeignObject(
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|         Relation,
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|         on_delete=models.CASCADE,
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|         from_fields=["model_non_concrete_id"],
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|         to_fields=["id"],
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|         related_name="fo_concrete_rel",
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|     )
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| 
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|     # GFK fields
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|     content_type_concrete = models.ForeignKey(
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|         ContentType, models.CASCADE, related_name="+"
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|     )
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|     object_id_concrete = models.PositiveIntegerField()
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|     content_object_concrete = GenericForeignKey(
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|         "content_type_concrete", "object_id_concrete"
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|     )
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| 
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|     # GR fields
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|     generic_relation_concrete = GenericRelation(Relation)
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| 
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| 
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| class ProxyPerson(Person):
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|     class Meta:
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|         proxy = True
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| 
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| 
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| class PersonThroughProxySubclass(ProxyPerson):
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|     pass
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| 
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| 
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| class Relating(models.Model):
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|     # ForeignKey to BasePerson
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|     baseperson = models.ForeignKey(
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|         BasePerson, models.CASCADE, related_name="relating_baseperson"
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|     )
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|     baseperson_hidden = models.ForeignKey(BasePerson, models.CASCADE, related_name="+")
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| 
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|     # ForeignKey to Person
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|     person = models.ForeignKey(Person, models.CASCADE, related_name="relating_person")
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|     person_hidden = models.ForeignKey(Person, models.CASCADE, related_name="+")
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| 
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|     # ForeignKey to ProxyPerson
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|     proxyperson = models.ForeignKey(
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|         ProxyPerson, models.CASCADE, related_name="relating_proxyperson"
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|     )
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|     proxyperson_hidden = models.ForeignKey(
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|         ProxyPerson, models.CASCADE, related_name="relating_proxyperson_hidden+"
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|     )
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| 
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|     # ManyToManyField to BasePerson
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|     basepeople = models.ManyToManyField(BasePerson, related_name="relating_basepeople")
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|     basepeople_hidden = models.ManyToManyField(BasePerson, related_name="+")
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| 
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|     # ManyToManyField to Person
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|     people = models.ManyToManyField(Person, related_name="relating_people")
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|     people_hidden = models.ManyToManyField(Person, related_name="+")
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| 
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| 
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| # ParentListTests models
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| class CommonAncestor(models.Model):
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|     pass
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| 
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| 
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| class FirstParent(CommonAncestor):
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|     first_ancestor = models.OneToOneField(
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|         CommonAncestor, models.CASCADE, primary_key=True, parent_link=True
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|     )
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| 
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| 
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| class SecondParent(CommonAncestor):
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|     second_ancestor = models.OneToOneField(
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|         CommonAncestor, models.CASCADE, primary_key=True, parent_link=True
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|     )
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| 
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| 
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| class Child(FirstParent, SecondParent):
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|     pass
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