from pydantic.v1 import BaseSettings


class Settings(BaseSettings):
    app_name: str = "Awesome API"
    admin_email: str
    items_per_user: int = 50

    class Config:

{* ../../docs_src/query_params_str_validations/tutorial002_an_py310.py hl[9] *}

Notice that the default value is still `None`, so the parameter is still optional.

But now, having `Query(max_length=50)` inside of `Annotated`, we are telling FastAPI that we want it to have **additional validation** for this value, we want it to have maximum 50 characters. 😎

/// tip

from typing import Annotated, Union

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(q: Annotated[Union[str, None], Query(max_length=50)] = None):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

name: Issue Workflow

on:
  issues:
    types:
      - opened

jobs:
  add-to-project:
    name: Add issue to project
    runs-on: ubuntu-latest
    steps:
      - uses: actions/add-to-project@v0.5.0
        with:
          project-url: https://github.com/orgs/miniohq/projects/2

from typing import Union

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(
    q: Union[str, None] = Query(
        default=None, min_length=3, max_length=50, pattern="^fixedquery$"
    ),
):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

def test_app():
    response = client.get("/info")
    data = response.json()
    assert data == {
        "app_name": "Awesome API",
        "admin_email": "******@****.***",
        "items_per_user": 50,

        },
    }
    for i in range(300)
]

LARGE_METADATA: dict[str, Any] = {
    "source": "benchmark",
    "version": 1,
    "flags": {"a": True, "b": False, "c": True},
    "notes": ["x" * 50, "y" * 50, "z" * 50],
}

LARGE_PAYLOAD: dict[str, Any] = {"items": LARGE_ITEMS, "metadata": LARGE_METADATA}


def dep_a():
    return 40


def dep_b(a: Annotated[int, Depends(dep_a)]):
    return a + 2

    byte[] key = fillByteArray(20, 0xaa);
    byte[] data = fillByteArray(50, 0xdd);

    checkSha1("125d7342b9ac11cd91a39af48aa17b4f63f175d3", key, data);
  }

  public void testRfc2202_hmacSha1_case4() {
    byte[] key = base16().lowerCase().decode("0102030405060708090a0b0c0d0e0f10111213141516171819");
    byte[] data = fillByteArray(50, 0xcd);

    checkSha1("4c9007f4026250c6bc8414f9bf50c86c2d7235da", key, data);
  }

{* ../../docs_src/query_params_str_validations/tutorial002_an_py310.py hl[9] *}

Nota que el valor por defecto sigue siendo `None`, por lo que el parámetro sigue siendo opcional.

from pydantic_settings import BaseSettings


class Settings(BaseSettings):
    app_name: str = "Awesome API"
    admin_email: str