Dectinc / datamodel-code-generator

Pydantic model generator for easy conversion of JSON, OpenAPI, JSON Schema, and YAML data sources.

datamodel-code-generator

This code generator creates pydantic model from an openapi file and others.

Help

See documentation for more details.

Supported source types

• OpenAPI 3 (YAML/JSON, OpenAPI Data Type)
• JSON Schema (JSON Schema Core/JSON Schema Validation)
• JSON/YAML/CSV Data (it will be converted to JSON Schema)
• Python dictionary (it will be converted to JSON Schema)

Implemented list

OpenAPI 3 and JsonSchema

DataType

• string (include patter/minLength/maxLenght)
• number (include maximum/exclusiveMaximum/minimum/exclusiveMinimum/multipleOf/le/ge)
• integer (include maximum/exclusiveMaximum/minimum/exclusiveMinimum/multipleOf/le/ge)
• boolean
• array
• object

String Format

• date
• datetime
• time
• password
• email
• idn-email
• uuid (uuid1/uuid2/uuid3/uuid4/uuid5)
• ipv4
• ipv6
• hostname
• decimal

Other schema

• enum (as enum.Enum or typing.Literal)
• allOf (as Multiple inheritance)
• anyOf (as typing.Union)
• oneOf (as typing.Union)
• $ref (http extra is required when resolving $ref for remote files.)
• $id (for JSONSchema)

Installation

To install datamodel-code-generator:

$ pip install datamodel-code-generator

http extra option

If you want to resolve $ref for remote files then you should specify http extra option.

$ pip install datamodel-code-generator[http]

Usage

The datamodel-codegen command:

usage: datamodel-codegen [-h] [--input INPUT] [--url URL] [--input-file-type {auto,openapi,jsonschema,json,yaml,dict,csv}] [--output OUTPUT]
                         [--base-class BASE_CLASS] [--field-constraints] [--field-extra-keys FIELD_EXTRA_KEYS [FIELD_EXTRA_KEYS ...]]
                         [--field-include-all-keys] [--snake-case-field] [--strip-default-none] [--disable-appending-item-suffix]
                         [--allow-population-by-field-name] [--enable-faux-immutability] [--use-default] [--force-optional] [--strict-nullable]
                         [--strict-types {str,bytes,int,float,bool} [{str,bytes,int,float,bool} ...]] [--disable-timestamp]
                         [--use-standard-collections] [--use-generic-container-types] [--use-schema-description] [--reuse-model]
                         [--enum-field-as-literal {all,one}] [--set-default-enum-member] [--empty-enum-field-name EMPTY_ENUM_FIELD_NAME]
                         [--class-name CLASS_NAME] [--custom-template-dir CUSTOM_TEMPLATE_DIR] [--extra-template-data EXTRA_TEMPLATE_DATA]
                         [--aliases ALIASES] [--target-python-version {3.6,3.7,3.8,3.9}] [--validation] [--encoding ENCODING] [--debug] [--version]

optional arguments:
  -h, --help            show this help message and exit
  --input INPUT         Input file/directory (default: stdin)
  --url URL             Input file URL. `--input` is ignore when `--url` is used
  --input-file-type {auto,openapi,jsonschema,json,yaml,dict,csv}
                        Input file type (default: auto)
  --output OUTPUT       Output file (default: stdout)
  --base-class BASE_CLASS
                        Base Class (default: pydantic.BaseModel)
  --field-constraints   Use field constraints and not con* annotations
  --field-extra-keys FIELD_EXTRA_KEYS [FIELD_EXTRA_KEYS ...]
                        Add extra keys to field parameters
  --field-include-all-keys
                        Add all keys to field parameters
  --snake-case-field    Change camel-case field name to snake-case
  --strip-default-none  Strip default None on fields
  --disable-appending-item-suffix
                        Disable appending `Item` suffix to model name in an array
  --allow-population-by-field-name
                        Allow population by field name
  --enable-faux-immutability
                        Enable faux immutability
  --use-default         Use default value even if a field is required
  --force-optional      Force optional for required fields
  --strict-nullable     Treat default field as a non-nullable field (Only OpenAPI)
  --strict-types {str,bytes,int,float,bool} [{str,bytes,int,float,bool} ...]
                        Use strict types
  --disable-timestamp   Disable timestamp on file headers
  --use-standard-collections
                        Use standard collections for type hinting (list, dict)
  --use-generic-container-types
                        Use generic container types for type hinting (typing.Sequence, typing.Mapping). If `--use-standard-collections` option is set,
                        then import from collections.abc instead of typing
  --use-schema-description
                        Use schema description to populate class docstring
  --reuse-model         Re-use models on the field when a module has the model with the same content
  --enum-field-as-literal {all,one}
                        Parse enum field as literal. all: all enum field type are Literal. one: field type is Literal when an enum has only one
                        possible value
  --set-default-enum-member
                        Set enum members as default values for enum field
  --empty-enum-field-name EMPTY_ENUM_FIELD_NAME
                        Set field name when enum value is empty (default: `_`)
  --class-name CLASS_NAME
                        Set class name of root model
  --custom-template-dir CUSTOM_TEMPLATE_DIR
                        Custom template directory
  --extra-template-data EXTRA_TEMPLATE_DATA
                        Extra template data
  --aliases ALIASES     Alias mapping file
  --target-python-version {3.6,3.7,3.8,3.9}
                        target python version (default: 3.7)
  --validation          Enable validation (Only OpenAPI)
  --encoding ENCODING   The encoding of input and output (default: UTF-8)
  --debug               show debug message
  --version             show version

Example

OpenAPI

# Generate models from a local file.
$ datamodel-codegen --input api.yaml --output model.py
# or directly from a URL.
$ datamodel-codegen --url https://<INPUT FILE URL> --output model.py

api.yaml

openapi: "3.0.0"
info:
  version: 1.0.0
  title: Swagger Petstore
  license:
    name: MIT
servers:
  - url: http://petstore.swagger.io/v1
paths:
  /pets:
    get:
      summary: List all pets
      operationId: listPets
      tags:
        - pets
      parameters:
        - name: limit
          in: query
          description: How many items to return at one time (max 100)
          required: false
          schema:
            type: integer
            format: int32
      responses:
        '200':
          description: A paged array of pets
          headers:
            x-next:
              description: A link to the next page of responses
              schema:
                type: string
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Pets"
        default:
          description: unexpected error
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Error"
                x-amazon-apigateway-integration:
                  uri:
                    Fn::Sub: arn:aws:apigateway:${AWS::Region}:lambda:path/2015-03-31/functions/${PythonVersionFunction.Arn}/invocations
                  passthroughBehavior: when_no_templates
                  httpMethod: POST
                  type: aws_proxy
    post:
      summary: Create a pet
      operationId: createPets
      tags:
        - pets
      responses:
        '201':
          description: Null response
        default:
          description: unexpected error
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Error"
                x-amazon-apigateway-integration:
                  uri:
                    Fn::Sub: arn:aws:apigateway:${AWS::Region}:lambda:path/2015-03-31/functions/${PythonVersionFunction.Arn}/invocations
                  passthroughBehavior: when_no_templates
                  httpMethod: POST
                  type: aws_proxy
  /pets/{petId}:
    get:
      summary: Info for a specific pet
      operationId: showPetById
      tags:
        - pets
      parameters:
        - name: petId
          in: path
          required: true
          description: The id of the pet to retrieve
          schema:
            type: string
      responses:
        '200':
          description: Expected response to a valid request
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Pets"
        default:
          description: unexpected error
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Error"
    x-amazon-apigateway-integration:
      uri:
        Fn::Sub: arn:aws:apigateway:${AWS::Region}:lambda:path/2015-03-31/functions/${PythonVersionFunction.Arn}/invocations
      passthroughBehavior: when_no_templates
      httpMethod: POST
      type: aws_proxy
components:
  schemas:
    Pet:
      required:
        - id
        - name
      properties:
        id:
          type: integer
          format: int64
        name:
          type: string
        tag:
          type: string
    Pets:
      type: array
      items:
        $ref: "#/components/schemas/Pet"
    Error:
      required:
        - code
        - message
      properties:
        code:
          type: integer
          format: int32
        message:
          type: string
    apis:
      type: array
      items:
        type: object
        properties:
          apiKey:
            type: string
            description: To be used as a dataset parameter value
          apiVersionNumber:
            type: string
            description: To be used as a version parameter value
          apiUrl:
            type: string
            format: uri
            description: "The URL describing the dataset's fields"
          apiDocumentationUrl:
            type: string
            format: uri
            description: A URL to the API console for each API

model.py:

# generated by datamodel-codegen:
#   filename:  api.yaml
#   timestamp: 2020-06-02T05:28:24+00:00

from __future__ import annotations

from typing import List, Optional

from pydantic import AnyUrl, BaseModel, Field


class Pet(BaseModel):
    id: int
    name: str
    tag: Optional[str] = None


class Pets(BaseModel):
    __root__: List[Pet]


class Error(BaseModel):
    code: int
    message: str


class Api(BaseModel):
    apiKey: Optional[str] = Field(
        None, description='To be used as a dataset parameter value'
    )
    apiVersionNumber: Optional[str] = Field(
        None, description='To be used as a version parameter value'
    )
    apiUrl: Optional[AnyUrl] = Field(
        None, description="The URL describing the dataset's fields"
    )
    apiDocumentationUrl: Optional[AnyUrl] = Field(
        None, description='A URL to the API console for each API'
    )


class Apis(BaseModel):
    __root__: List[Api]

Related projects

fastapi-code-generator

This code generator creates FastAPI app from an openapi file.

https://github.com/koxudaxi/fastapi-code-generator

pydantic-pycharm-plugin

A JetBrains PyCharm plugin for pydantic.

https://github.com/koxudaxi/pydantic-pycharm-plugin

PyPi

https://pypi.org/project/datamodel-code-generator

License

datamodel-code-generator is released under the MIT License. http://www.opensource.org/licenses/mit-license