FastAPI后台开发基础（6）：Body 参数的几种用法

class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None


class User(BaseModel):
    username: str
    full_name: str | None = None

@app.put("/items/{item_id}")
async def update_item(item_id: int, item: Item, user: User):
    """
    curl -X 'PUT' \
    'http://127.0.0.1:18081/items/12345' \
    -H 'accept: application/json' \
    -H 'Content-Type: application/json' \
    -d '{
        "item": {
          "name": "nn",
          "description": "dd",
          "price": 1,
          "tax": 2
        },
        "user": {
          "username": "uu",
          "full_name": "ff"
        }
    }'

    """
    results = {"item_id": item_id, "item": item, "user": user}
    return results

@app.put("/items2/{item_id}")
async def update_item2(
    *,
    item_id: int,
    item: Item,
    user: User,
    importance: Annotated[int, Body(gt = 0)],  # instruct FastAPI to treat it as another body key using Body
    q: str | None = None,
):
    """
    declare additional query parameters whenever you need, additional to any body parameters
    在任何需要的时候声明额外的查询参数，作为对任何主体参数的补充
    curl -X 'PUT' \
    'http://127.0.0.1:18081/items2/1234?q=qqqqqq' \
    -H 'accept: application/json' \
    -H 'Content-Type: application/json' \
    -d '{
        "item": {
          "name": "nnnnn",
          "description": "ddddd",
          "price": 0,
          "tax": 0
        },
        "user": {
          "username": "uuuuu",
          "full_name": "ffffff"
        },
        "importance": 1
    }'

    The asterisk (*) in the function definition only enforces keyword-only arguments in Python.
    It doesn't change how FastAPI interprets or processes the parameters.
    The determination of whether a parameter is a body parameter, query parameter, or path parameter is based on:
        The parameter's type annotation
        The use of FastAPI's special classes like Query(), Body(), etc.
    """
    results = {"item_id": item_id, "item": item, "user": user, "importance": importance}
    if q:
        results.update({"q": q})
    return results

@app.put("/items3/{item_id}")
async def update_item3(
    item_id: int,
    item: Item,
    user: User,
    importance: Annotated[int, Body(gt = 0)],  # instruct FastAPI to treat it as another body key using Body
    q: str | None = None,
):
    """
   curl -X 'PUT' \
   'http://127.0.0.1:18081/items3/123?q=qqqq' \
   -H 'accept: application/json' \
   -H 'Content-Type: application/json' \
   -d '{
       "item": {
         "name": "string",
         "description": "string",
         "price": 0,
         "tax": 0
       },
       "user": {
         "username": "string",
         "full_name": "string"
       },
       "importance": 1
   }'
    """
    results = {"item_id": item_id, "item": item, "user": user, "importance": importance}
    if q:
        results.update({"q": q})
    return results

@app.put("/items4/{item_id}")
async def update_item4(item_id: int, my_custom_item: Annotated[Item, Body(embed = True)]):
    """
    if you want it to expect a JSON with a key my_custom_item and inside of it the model contents,
    as it does when you declare extra body parameters,
    you can use the special Body parameter embed

    curl -X 'PUT' \
      'http://127.0.0.1:18081/items4/1234' \
      -H 'accept: application/json' \
      -H 'Content-Type: application/json' \
      -d '{
      "my_custom_item": {
        "name": "string",
        "description": "string",
        "price": 0,
        "tax": 0
      }
    }'
    """
    results = {"item_id": item_id, "item": my_custom_item}
    return results

@app.put("/items5/{item_id}")
async def update_item5(item_id: int, my_custom_item: Item):
    """
    curl -X 'PUT' \
      'http://127.0.0.1:18081/items5/1234' \
      -H 'accept: application/json' \
      -H 'Content-Type: application/json' \
      -d '{
      "name": "string",
      "description": "string",
      "price": 0,
      "tax": 0
    }'
    """
    results = {"item_id": item_id, "item": my_custom_item}
    return results