In a nutshell

>>> import enum
>>> import json
>>> import typing as t
>>> import middle
>>> from middle_schema.openapi import parse

>>> @enum.unique
... class PlatformEnum(str, enum.Enum):
...     XBOX1 = "XBOX1"
...     PLAYSTATION4 = "PLAYSTATION4"
...     PC = "PC"

>>> @enum.unique
... class LanguageEnum(enum.IntEnum):
...     ENGLISH = 1
...     JAPANESE = 2
...     SPANISH = 3
...     GERMAN = 4
...     PORTUGUESE = 5

>>> @enum.unique
... class CityRegionEnum(str, enum.Enum):
...     TROPICAL = "TROPICAL"
...     TEMPERATE = "TEMPERATE"
...     BOREAL = "BOREAL"

>>> class City(middle.Model):
...     __description__ = "One awesome city built"
...     name = middle.field(type=str, description="The city name")
...     region = middle.field(
...         default=CityRegionEnum.TEMPERATE,
...         type=CityRegionEnum,
...         description="The region this city is located",
...     )

>>> class Player(middle.Model):
...     nickname = middle.field(
...         type=str, description="The nickname of the player over the internet"
...     )
...     youtube_channel = middle.field(
...         type=str, description="The YouTube channel of the player", default=None
...     )

>>> class Game(middle.Model):
...     __description__ = "An electronic game model"
...     name = middle.field(type=str, description="The name of the game")
...     platform = middle.field(
...         type=PlatformEnum, description="Which platform it runs on"
...     )
...     score = middle.field(
...         type=float,
...         description="The average score of the game",
...         minimum=0,
...         maximum=10,
...         multiple_of=0.1,
...     )
...     resolution_tested = middle.field(
...         type=str,
...         description="The resolution which the game was tested",
...         pattern="^\d+x\d+$",
...     )
...     genre = middle.field(
...         type=t.List[str],
...         description="One or more genres this game is part of",
...         min_items=1,
...         unique_items=True,
...     )
...     rating = middle.field(
...         type=t.Dict[str, float],
...         description="Ratings given on specialized websites",
...         min_properties=3,
...     )
...     players = middle.field(
...         type=t.Set[str],
...         description="Some of the notorious players of this game",
...     )
...     language = middle.field(
...         type=LanguageEnum, description="The main language of the game"
...     )
...     awesome_city = middle.field(type=City)
...     remarkable_resources = middle.field(
...         type=t.Union[Player, City],
...         description="Some remarkable resources of this game over the internet",
...     )

>>> api = parse(Game)

>>> json.dumps(api.specification, indent=4, sort_keys=True)
{
    "description": "An electronic game model",
    "properties": {
        "awesome_city": {
            "description": "One awesome city built",
            "properties": {
                "name": {
                    "description": "The city name",
                    "type": "string"
                },
                "region": {
                    "choices": [
                        "TROPICAL",
                        "TEMPERATE",
                        "BOREAL"
                    ],
                    "description": "The region this city is located",
                    "type": "string"
                }
            },
            "required": [
                "name"
            ],
            "type": "object"
        },
        "genre": {
            "description": "One or more genres this game is part of",
            "items": {
                "type": "string"
            },
            "minItems": 1,
            "type": "array",
            "uniqueItems": true
        },
        "language": {
            "choices": [
                1,
                2,
                3,
                4,
                5
            ],
            "description": "The main language of the game",
            "format": "int64",
            "type": "integer"
        },
        "name": {
            "description": "The name of the game",
            "type": "string"
        },
        "platform": {
            "choices": [
                "XBOX1",
                "PLAYSTATION4",
                "PC"
            ],
            "description": "Which platform it runs on",
            "type": "string"
        },
        "players": {
            "description": "Some of the notorious players of this game",
            "items": {
                "properties": {
                    "nickname": {
                        "description": "The nickname of the player over the internet",
                        "type": "string"
                    },
                    "youtube_channel": {
                        "description": "The YouTube channel of the player",
                        "type": "string"
                    }
                },
                "required": [
                    "nickname"
                ],
                "type": "object"
            },
            "type": "array"
        },
        "rating": {
            "additionalProperties": {
                "format": "double",
                "type": "number"
            },
            "description": "Ratings given on specialized websites",
            "minProperties": 3,
            "type": "object"
        },
        "remarkable_resources": {
            "anyOf": [
                {
                    "properties": {
                        "nickname": {
                            "description": "The nickname of the player over the internet",
                            "type": "string"
                        },
                        "youtube_channel": {
                            "description": "The YouTube channel of the player",
                            "type": "string"
                        }
                    },
                    "required": [
                        "nickname"
                    ],
                    "type": "object"
                },
                {
                    "description": "One awesome city built",
                    "properties": {
                        "name": {
                            "description": "The city name",
                            "type": "string"
                        },
                        "region": {
                            "choices": [
                                "TROPICAL",
                                "TEMPERATE",
                                "BOREAL"
                            ],
                            "description": "The region this city is located",
                            "type": "string"
                        }
                    },
                    "required": [
                        "name"
                    ],
                    "type": "object"
                }
            ],
            "description": "Some remarkable resources of this game over the internet"
        },
        "resolution_tested": {
            "description": "The resolution which the game was tested",
            "pattern": "^\\d+x\\d+$",
            "type": "string"
        },
        "score": {
            "description": "The average score of the game",
            "format": "double",
            "maximum": 10,
            "minimum": 0,
            "multipleOf": 0.1,
            "type": "number"
        }
    },
    "required": [
        "name",
        "platform",
        "score",
        "resolution_tested",
        "genre",
        "rating",
        "players",
        "language",
        "awesome_city",
        "remarkable_resources"
    ],
    "type": "object"
}

v0.2.0 on 2018-08-01

• Small refactoring on the Skeleton parser;

• OpenAPI component and schema generation of middle models;

• 99%+ of code coverage.

v0.1.0 on 2018-07-26

• First release on PyPI. Not stable.