fastAPI(3)--嵌套模型、复杂数据类型

骑猪看日落 2022-12-26 08:23 146阅读 0赞

1. 嵌套模型

1). 模型的属性可以是数据集合类型，比如list，dict,tuple,set等等。

class Item(BaseModel):
        name: str
        description: str = None
        price: float
        tax: float = None
        tags: list = []

from typing import List
    
    class Item(BaseModel):
        name: str
        description: str = None
        price: float
        tax: float = None
        tags: List[str] = []

from typing import Set
    
    class Item(BaseModel):
        name: str
        description: str = None
        price: float
        tax: float = None
        tags: Set[str] = set()

也可以直接定义一个字典类型的body，通常指定了键和值的数据类型。

from typing import Dict
    from fastapi import FastAPI
    
    app = FastAPI()
    
    
    @app.post("/index-weights/")
    async def create_index_weights(weights: Dict[int, float]):
        return weights

2). 嵌套模型

from typing import Set
    
    from fastapi import FastAPI
    from pydantic import BaseModel
    
    app = FastAPI()
    
    
    class Image(BaseModel):
        url: str
        name: str
    
    class Item(BaseModel):
        name: str
        description: str = None
        price: float
        tax: float = None
        tags: Set[str] = []
        image: Image = None
    
    @app.put("/items/{item_id}")
    async def update_item(*, item_id: int, item: Item):
        results = {"item_id": item_id, "item": item}
        return results

FastAPI期望的Request Body内容格式如下：

{
        "name": "Foo",
        "description": "The pretender",
        "price": 42.0,
        "tax": 3.2,
        "tags": ["rock", "metal", "bar"],
        "image": {
            "url": "http://example.com/baz.jpg",
            "name": "The Foo live"
        }
    }

也可以把Pydantic模型作为list、set等集合类型的元素类型。

from typing import List, Set
    from fastapi import FastAPI
    from pydantic import BaseModel, HttpUrl
    
    app = FastAPI()
    
    
    class Image(BaseModel):
        url: HttpUrl
        name: str
    
    
    class Item(BaseModel):
        name: str
        description: str = None
        price: float
        tax: float = None
        tags: Set[str] = []
        images: List[Image] = None
    
    
    @app.put("/items/{item_id}")
    async def update_item(*, item_id: int, item: Item):
        results = {"item_id": item_id, "item": item}
        return results

内容格式如下：

{
        "name": "Foo",
        "description": "The pretender",
        "price": 42.0,
        "tax": 3.2,
        "tags": [
            "rock",
            "metal",
            "bar"
        ],
        "images": [
            {
                "url": "http://example.com/baz.jpg",
                "name": "The Foo live"
            },
            {
                "url": "http://example.com/dave.jpg",
                "name": "The Baz"
            }
        ]
    }

3). 深层嵌套模型

from typing import List, Set
    from fastapi import FastAPI
    from pydantic import BaseModel, HttpUrl
    
    app = FastAPI()
    
    class Image(BaseModel):
        url: HttpUrl
        name: str
    
    class Item(BaseModel):
        name: str
        description: str = None
        price: float
        tax: float = None
        tags: Set[str] = []
        images: List[Image] = None
    
    class Offer(BaseModel):
        name: str
        description: str = None
        price: float
        items: List[Item]
    
    @app.post("/offers/")
    async def create_offer(*, offer: Offer):
        return offer

2.复杂数据类型

1).UUID
    一个标准的“通用唯一标识符”，在许多数据库和系统中通常作为ID使用
    在requests和responses中被认为是字符串类型。
    
    2).datetime.datetime
    标准的Python datetime.datetime。
    在requests和responses中被认为是字符串类型，例如"2008-09-15T15:53:00+05:00"。
    
    3).datetime.date
    标准的Python datetime.date。
    在requests和responses中被认为是字符串类型，例如 "2008-09-15"。
    
    4).datetime.time
    标准的Python datetime.time。
    在requests和responses中被认为是字符串类型，例如 "14:23:55.003"。
    
    5).datetime.timedelta
    标准的Python datetime.timedelta。
    在requests和responses中被认为是表示秒数的float类型，例如 "2008-09-15"。
    
    6).frozenset
    在requests和responses中等同于set。
    在requests中，列表数据会先进行去重，然后转换成set。
    在responses中，set会被转换成list。
    
    7).bytes
    标准的Python bytes。
    在requests和responses中被认为是字符串类型。
    
    8).Decimal
    标准的Python Decimal。
    在requests和responses中被认为是float类型。
    
    以下是示例：

from datetime import datetime, time, timedelta
    from uuid import UUID
    
    from fastapi import Body, FastAPI
    
    app = FastAPI()
    
    
    @app.put("/items/{item_id}")
    async def read_items(
            item_id: UUID,
            start_datetime: datetime = Body(None),
            end_datetime: datetime = Body(None),
            repeat_at: time = Body(None),
            process_after: timedelta = Body(None),
    ):
        start_process = start_datetime + process_after
        duration = end_datetime - start_process
        return {
            "item_id": item_id,
            "start_datetime": start_datetime,
            "end_datetime": end_datetime,
            "repeat_at": repeat_at,
            "process_after": process_after,
            "start_process": start_process,
            "duration": duration,
        }