fastAPI(2)--请求参数、路径参数、多body

阳光穿透心脏的1/2处 2022-12-26 04:49 114阅读 0赞

1.请求参数附加信息

#!/usr/bin/env python
    # encoding: utf-8
    
    from fastapi import FastAPI, Query
    from typing import Optional
    import uvicorn
    
    app = FastAPI()
    
    @app.get('/items/')
    async def read_items(q: Optional[str] = Query(None, min_length=3, max_length=50)):
        results = {'message': 'item'}
        if q:
            results.update({'q': q})
        return results
    
    if __name__ == '__main__':
        uvicorn.run(app=app, host='127.0.0.1', port=8000)

使用Query作为默认值, 将参数设置min\_length为3,max\_length为50  
添加正则表达式 q: Optional\[str\] = Query(None, regex="^fixedquery$")  
设置默认值 q: str = Query("fixedquery", min\_length=3)  
title：参数标题  
description：参数描述信息  
deprecated：表示参数即将过期  
alias：参数别名  
当不需要声明更多的验证或元数据时，q只需不声明默认值即可使查询参数成为必需：q: str，  
当使用Query声明它时，可以将...用作第一个参数，代表必填 eg: q: str = Query(..., min\_length=3)

@app.get('/items/')
    async def read_item(q: str = Query(..., min_length=3)):
    """使用Query声明它时，可以将...用作第一个参数"""
        results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
        if q:
            results.update({"q": q})
        return results

2.请求参数列表

#!/usr/bin/env python
    # encoding: utf-8
    
    from fastapi import FastAPI, Query
    from typing import Optional, List
    import uvicorn
    
    app = FastAPI()
    
    @app.get('/items_list/')
    async def read_item_list(q: Optional[List[str]] = Query(None)):
        query_items = {"q": q}
        return query_items
    
    
    if __name__ == '__main__':
        uvicorn.run(app=app, host='127.0.0.1', port=8000)

访问：http://localhost:8000/items/?q=foo&q=bar  
    得到结果：\{"q": \["foo", "bar"\]\}  
    (1).请求参数列表的缺省值设置：q: List\[str\] = Query(\["foo", "bar"\])  
    (2).可以用list代替List\[str\]，但这样的话FastAPI就无法校验列表内容了: q: list = Query(None)

3. 路径参数附加信息

#!/usr/bin/env python
    # encoding: utf-8
    
    from fastapi import FastAPI, Query, Path
    from typing import Optional
    import uvicorn
    
    app = FastAPI()
    
    @app.get('/item_path/{item_id}')
    async def read_items_path(
            item_id: int = Path(..., title='The ID of the item to get'),
            q: Optional[str] = Query(None, alias='item-query'),
            size: float = Query(1, gt=0, lt=10.5)
    ):
        """
        路径参数附加信息
        路径参数在URL里是必选的，因此Path的第一个参数是...，即使你传递了None或其他缺省值，也不会影响参数的必选性。
        """
        results = {'item_id': item_id, 'size': size}
        if q:
            results.update({"q": q})
        return results
    
    
    if __name__ == '__main__':
        uvicorn.run(app=app, host='127.0.0.1', port=8000)

4. 混合`Path`，`Query`和body参数

#!/usr/bin/env python
    # encoding: utf-8
    
    from fastapi import FastAPI, Query, Path
    import uvicorn
    from pydantic import BaseModel
    
    app = FastAPI()
    
    class Item(BaseModel):
        name: str
        description: str = None
        price: float
        tax: float = None
    
    """
    (1).如果把带有缺省值的参数放在了不带缺省值的参数前面，Python会发出运行警告。
    因此在实际使用时，我们应当把不带缺省值的参数放在前面，无论这个参数是路径参数还是请求参数。
    query: str, item_id: int = Path(..., title="The ID of the item to get")
    (2).通过传递 * 作为第一个参数，就解决了上面的参数顺序问题。
    *, item_id: int = Path(..., title="The ID of the item to get"), q: str
    """
    @app.post('/body/{item_id}')
    async def body(
            query: str,
            item_id: int = Path(..., title='', ge=10, le=100),
            item: Item = None
    ):
        result = {'item_id': item_id}
        if query:
            result.update({"query": query})
        if item:
            result.update({"item": item})
        return result
    
    
    if __name__ == '__main__':
        uvicorn.run(app)

5. 多body

from typing import Optional
    from fastapi import FastAPI
    from pydantic import BaseModel
    
    app = FastAPI()
    
    class Item(BaseModel):
        name: str
        description: Optional[str] = None
        price: float
        tax: Optional[float] = None
    
    class User(BaseModel):
        username: str
        full_name: Optional[str] = None
    
    @app.put("/items/{item_id}")
    async def update_item(item_id: int, item: Item, user: User):
        results = {"item_id": item_id, "item": item, "user": user}
        return results

响应参数：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zOTQ2MTQ4Nw_size_16_color_FFFFFF_t_70][]

6. body 的奇异值

from typing import Optional
    from fastapi import Body, FastAPI
    from pydantic import BaseModel
    
    app = FastAPI()
    
    class Item(BaseModel):
        name: str
        description: Optional[str] = None
        price: float
        tax: Optional[float] = None
    
    
    class User(BaseModel):
        username: str
        full_name: Optional[str] = None
    
    
    @app.put("/items/{item_id}")
    async def update_item(item_id: int, item: Item, user: User, importance: int = Body(...)):
        results = {"item_id": item_id, "item": item, "user": user, "importance": importance}
        return results

以上相当于将importance 参数 与User  Item 组合起来形成一个大的body

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zOTQ2MTQ4Nw_size_16_color_FFFFFF_t_70 1][]

7. 嵌入单一body

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

item: Item = Body(..., embed=True)
    这里"item"是Request Body内部数据内容的键值，那么我们就需要利用Body方法的embed参数，才能正确解析出Request Body内容。使用后参数形式为：
    {
        "item": {
            "name": "Foo",
            "description": "The pretender",
            "price": 42.0,
            "tax": 3.2
        }
    }

8. body 内参数验证 Feild

需注意的：Feild 是基于pydantic 导出的

from typing import Optional
    from fastapi import Body, FastAPI
    from pydantic import BaseModel, Field
    
    app = FastAPI()
    
    class Item(BaseModel):
        name: str
        description: Optional[str] = Field(
            None, title="The description of the item", max_length=300
        )
        price: float = Field(..., gt=0, description="The price must be greater than zero")
        tax: Optional[float] = None
    
    @app.put("/items/{item_id}")
    async def update_item(item_id: int, item: Item = Body(..., embed=True)):
        results = {"item_id": item_id, "item": item}
        return results

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zOTQ2MTQ4Nw_size_16_color_FFFFFF_t_70]: /images/20221120/a7295fa08103464f99dc0da3eea36437.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zOTQ2MTQ4Nw_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/2020120321212522.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zOTQ2MTQ4Nw==,size_16,color_FFFFFF,t_70