Why

django2pydantic is the most complete Pydantic schemas based on Django models.

What

django2pydantic is a library that allows to define Pydantic schemas based on Django database models.

Similar libraries:

• Djantic
• Django Ninja Schema
• Ninja Schema

Key features

• Supports all Django model field types
• Supports @property decorated Django model methods
• Supports all Django model relation fields:
  • ForeignKey, OneToOneField, ManyToManyField
  • The reverse relations of the above (ManyToOneRel, OneToOneRel, ManyToManyRel)
• Supports defining nested relations
• Provides as complete OpenAPI schema details as possible

How to use

See usage example here.

Django fields blank and null

There are some nuances related to the use of blank and null in Django fields and how they impact the output pydantic types, but generally:

• If null=True the output type will be Optional (i.e. str | None).
• If blank=True the field will be optional (with exceptions). This is to be more in line with the Django admin/form validation behavior.
• Whether the field is required is determined by the default value (can be overridden).
  • If the default is PydanticUndefined, the field is always required.
  • If the default is None (or "" in case of string), the field is optional.
• If null=False and blank=True, the field typically require implementing clean() on the model in order to programmatically supply any missing values. In our case, the required/default value can vary depending on field type in a way that user does not need to concern with implementing clean().

String-based fields

This covers the following Django field types:

• CharField
• SlugField
• EmailField
• URLField
• TextField

Configuration	Required	Default (If not specified)	Type	Min length	Comments
null=True, blank=True	Optional	None	str | None	None	There's 2 ways to represent "no data" in the DB: null and "" (not recommended)
null=True, blank=False	Required	PydanticUndefined	str | None	1	• There's 2 ways to represent "no data" in the DB: null and "" (not recommended) • However, with min_length, we eliminate "" from being a valid input
null=False, blank=True	Optional	""	str	None	Default is "" since null is not allowed
null=False, blank=False	Required	PydanticUndefined	str	1

Non-string-based fields

This covers the following Django field types:

• IntegerField
• SmallIntegerField
• IntegerField
• BigIntegerField
• PositiveSmallIntegerField
• PositiveIntegerField
• PositiveBigIntegerField
• FloatField
• DecimalField
• BinaryField
• BooleanField
• DateField
• DateTimeField
• DurationField
• FileField
• FilePathField
• GenericIPAddressField
• ImageField
• JSONField
• TimeField
• UUIDField

[FieldType] varies depending on the Django field type

Configuration	Required	Default (If not specified)	Type	Comments
null=True, blank=True	Optional	None	[FieldType] | None
null=True, blank=False	Required	PydanticUndefined	[FieldType] | None
null=False, blank=True	Required	PydanticUndefined	[FieldType]	Unlike string-based fields, without a specified default value, there's no valid empty value to be stored in database thus making this required
null=False, blank=False	Required	PydanticUndefined	[FieldType]

Relational fields

This covers the following Django field types:

• ForeignKey
• OneToOneField
• ManyToManyField
• ManyToOneRel
• OneToOneRel
• ManyToManyRel

[PkType] varies depending on model's primary key type

ForeignKey, OneToOneField

Configuration	Required	Default (If not specified)	Type	Comments
null=True, blank=True	Optional	None	[PkType] | None
null=True, blank=False	Required	PydanticUndefined	[PkType] | None
null=False, blank=True	Required	PydanticUndefined	[PkType]	Unlike string-based fields, without a specified default value, there's no valid empty value to be stored in database thus making this required
null=False, blank=False	Required	PydanticUndefined	[PkType]

ManyToManyField

null has no effect since there is no way to require a relationship at the database level. Ref: https://docs.djangoproject.com/en/5.1/ref/models/fields/#manytomanyfield

Configuration	Required	Default (If not specified)	Type	Comments
blank=True	Optional	None	list[PkType] | None
blank=False	Required	PydanticUndefined	list[PkType] | None

OneToOneRel

This field is created as a result of OneToOneField and is not directly configurable.

Required	Default (If not specified)	Type	Comments
Optional	None	[PkType] | None
Optional	None	[PkType] | None
Optional	None	[PkType] | None
Optional	None	[PkType] | None

ManyToOneRel, ManyToManyRel

These fields are created as a result of ForeignKey, ManyToManyField and are not directly configurable.

Required	Default (If not specified)	Type	Comments
Optional	None	list[PkType] | None
Optional	None	list[PkType] | None
Optional	None	list[PkType] | None
Optional	None	list[PkType] | None