This module contains utilities for creating schemas from JSON schemas. More...

Classes
class	FieldInfo

Functions
schemas.schema.Schema	create_schema (dict[str, typing.Any] schema, registry=Registry())
	Create a Schema object from a JSON schema object.

str	_resolve_new_url (str uri, str ref)
	Adapted from https://github.com/python-jsonschema/referencing/blob/main/referencing/_core.py#L667.

None	_validate_json_schema (dict[str, typing.Any] schema)

typing.Type	_convert_json_schema_to_our_schema (dict[str, typing.Any] schema, dict[int, typing.Type] json_schema_id_to_schema)
	Recursively handle all types needed to fully determine the type of a schema.

	_extract_fields_from_object_type (typing.Type object_type)

typing.Type	_handle_anyOf (dict[str, typing.Any] schema, dict[int, typing.Type] json_schema_id_to_schema)

typing.Type[typing.Any\|None]	_infer_type (dict[str, typing.Any] schema, dict[int, typing.Type] json_schema_id_to_schema)
	Infer more specific types.

typing.Any	_get_literal (dict[str, typing.Any] schema)

typing.Type	_handle_literal (typing.Any literal, typing.Type obtained_type, dict[str, typing.Any] schema, dict[int, typing.Type] json_schema_id_to_schema)

typing.Type	_handle_str_with_metadata (dict[str, typing.Any] schema)
	Handle string type with metadata such as maxLength, minLength, and pattern.

typing.Type	_handle_numeric_with_metadata (dict[str, typing.Any] schema, typing.Type numeric_type)
	Handle numeric types (int or float) with metadata such as minimum, maximum, exclusiveMinimum, and exclusiveMaximum.

typing.Type	_create_custom_type (dict[str, typing.Any] schema, dict[int, typing.Type] json_schema_id_to_schema)

typing.Type	_handle_list_metadata (dict[str, typing.Any] schema, dict[int, typing.Type] json_schema_id_to_schema)
	Handle cases where the obtained type is a list.

typing.Type[typing.Any\|None]	_obtain_type (dict[str, typing.Any] schema, dict[int, typing.Type] json_schema_id_to_schema)
	Directly obtain type information from this schema's type keyword.

	_merge_referenced_schema (dict[str, typing.Any] schema, set[int] memo)

	_merge_key (dict[str, typing.Any] schema, str ref_key, typing.Any reference_value)

	_recursive_resolve_reference (str base_uri, typing.Any schema, Registry registry, set[int] memo)

	_resolve_reference (dict[str, typing.Any] schema, str key, typing.Any resolver)

Variables
int	_counter

Detailed Description

This module contains utilities for creating schemas from JSON schemas.

Function Documentation

◆ _convert_json_schema_to_our_schema()

typing.Type formatron.schemas.json_schema._convert_json_schema_to_our_schema	(	dict[str, typing.Any]	schema,
		dict[int, typing.Type]	json_schema_id_to_schema )

protected

Recursively handle all types needed to fully determine the type of a schema.

Definition at line 156 of file json_schema.py.

◆ _create_custom_type()

typing.Type formatron.schemas.json_schema._create_custom_type	(	dict[str, typing.Any]	schema,
		dict[int, typing.Type]	json_schema_id_to_schema )

protected

Definition at line 280 of file json_schema.py.

◆ _extract_fields_from_object_type()

formatron.schemas.json_schema._extract_fields_from_object_type ( typing.Type object_type )

protected

Definition at line 173 of file json_schema.py.

◆ _get_literal()

typing.Any formatron.schemas.json_schema._get_literal ( dict[str, typing.Any] schema )

protected

Definition at line 225 of file json_schema.py.

◆ _handle_anyOf()

typing.Type formatron.schemas.json_schema._handle_anyOf	(	dict[str, typing.Any]	schema,
		dict[int, typing.Type]	json_schema_id_to_schema )

protected

Definition at line 180 of file json_schema.py.

◆ _handle_list_metadata()

typing.Type formatron.schemas.json_schema._handle_list_metadata	(	dict[str, typing.Any]	schema,
		dict[int, typing.Type]	json_schema_id_to_schema )

protected

Handle cases where the obtained type is a list.

Definition at line 296 of file json_schema.py.

◆ _handle_literal()

typing.Type formatron.schemas.json_schema._handle_literal	(	typing.Any	literal,
		typing.Type	obtained_type,
		dict[str, typing.Any]	schema,
		dict[int, typing.Type]	json_schema_id_to_schema )

protected

Definition at line 230 of file json_schema.py.

◆ _handle_numeric_with_metadata()

typing.Type formatron.schemas.json_schema._handle_numeric_with_metadata	(	dict[str, typing.Any]	schema,
		typing.Type	numeric_type )

protected

Handle numeric types (int or float) with metadata such as minimum, maximum, exclusiveMinimum, and exclusiveMaximum.

Definition at line 263 of file json_schema.py.

◆ _handle_str_with_metadata()

typing.Type formatron.schemas.json_schema._handle_str_with_metadata ( dict[str, typing.Any] schema )

protected

Handle string type with metadata such as maxLength, minLength, and pattern.

Definition at line 243 of file json_schema.py.

◆ _infer_type()

typing.Type[typing.Any \| None] formatron.schemas.json_schema._infer_type	(	dict[str, typing.Any]	schema,
		dict[int, typing.Type]	json_schema_id_to_schema )

protected

Infer more specific types.

Definition at line 193 of file json_schema.py.

◆ _merge_key()

formatron.schemas.json_schema._merge_key	(	dict[str, typing.Any]	schema,
		str	ref_key,
		typing.Any	reference_value )

protected

Definition at line 380 of file json_schema.py.

◆ _merge_referenced_schema()

formatron.schemas.json_schema._merge_referenced_schema	(	dict[str, typing.Any]	schema,
		set[int]	memo )

protected

Definition at line 361 of file json_schema.py.

◆ _obtain_type()

typing.Type[typing.Any\|None] formatron.schemas.json_schema._obtain_type	(	dict[str, typing.Any]	schema,
		dict[int, typing.Type]	json_schema_id_to_schema )

protected

Directly obtain type information from this schema's type keyword.

Definition at line 324 of file json_schema.py.

◆ _recursive_resolve_reference()

formatron.schemas.json_schema._recursive_resolve_reference	(	str	base_uri,
		typing.Any	schema,
		Registry	registry,
		set[int]	memo )

protected

Definition at line 399 of file json_schema.py.

◆ _resolve_new_url()

str formatron.schemas.json_schema._resolve_new_url	(	str	uri,
		str	ref )

protected

Adapted from https://github.com/python-jsonschema/referencing/blob/main/referencing/_core.py#L667.

Definition at line 133 of file json_schema.py.

◆ _resolve_reference()

formatron.schemas.json_schema._resolve_reference	(	dict[str, typing.Any]	schema,
		str	key,
		typing.Any	resolver )

protected

Definition at line 421 of file json_schema.py.

◆ _validate_json_schema()

None formatron.schemas.json_schema._validate_json_schema ( dict[str, typing.Any] schema )

protected

Definition at line 138 of file json_schema.py.

◆ create_schema()

schemas.schema.Schema formatron.schemas.json_schema.create_schema	(	dict[str, typing.Any]	schema,
			registry = Registry() )

Create a Schema object from a JSON schema object.

This function takes a JSON schema and converts it into a Schema object that can be used for data validation and serialization. Currently, only the following JSON Schema features are supported:

type keyword
minLength, maxLength, pattern keywords for string type
substringOf keyword for string type
minimum, maximum, exclusiveMinimum, exclusiveMaximum keywords for number type and integer type
items keyword
- optionally with minItems, maxItems, prefixItems constraints
properties keyword
- Due to implementation limitations, we always assume additionalProperties is false.
- Note that properties is optional for object type.
enum and const keyword
- This includes advanced enum types such as array and object.
- Note that if both enum(or const) and type are present, type will be ignored.
required keyword
anyOf keyword
- This currently does not support factoring out common parts of the subschemas(like https://json-schema.org/understanding-json-schema/reference/combining#factoringschemas)
Schema references ($ref and $dynamicRef)
- Hence, all types of schema identifications($defs, $id, $anchor, $dynamicAnchor) are supported.
- This includes recursive schema references.
  - Recursive array references(like [[[[...]]]]) are not supported yet.
- Due to implementation limitations, duplicate constraint keywords in both referrers and referents are not allowed.
  - This bound is expected to be loosened in future versions of Formatron where "easily mergeable" constraint keywords will be merged.

Requirements

The input schema must be a valid JSON Schema according to the JSON Schema Draft 2020-12 standard
The root schema's type must be exactly "object" or "array" or both
The schema must have a valid '$id' and '$schema' fields
All references must be resolvable within the given schema and registry

Parameters

schema	A dictionary representing a valid JSON schema.
registry	A Registry object containing additional schema definitions. Defaults to an empty Registry.

Returns: schemas A Schema object representing the input JSON schema.

Exceptions

jsonschema	If the input schema is not a valid JSON Schema.
ValueError	If there are issues with schema references, constraints or requirements.

Definition at line 115 of file json_schema.py.

Variable Documentation

◆ _counter

int formatron.schemas.json_schema._counter

protected

Definition at line 67 of file json_schema.py.

Classes

Functions

Variables

Detailed Description

Function Documentation

◆ _convert_json_schema_to_our_schema()

◆ _create_custom_type()

◆ _extract_fields_from_object_type()

◆ _get_literal()

◆ _handle_anyOf()

◆ _handle_list_metadata()

◆ _handle_literal()

◆ _handle_numeric_with_metadata()

◆ _handle_str_with_metadata()

◆ _infer_type()

◆ _merge_key()

◆ _merge_referenced_schema()

◆ _obtain_type()

◆ _recursive_resolve_reference()

◆ _resolve_new_url()

◆ _resolve_reference()

◆ _validate_json_schema()

◆ create_schema()

Variable Documentation

◆ _counter