# Sub-dependencias { #sub-dependencies }

Puedes crear dependencias que tengan **sub-dependencias**.

Pueden ser tan **profundas** como necesites.

**FastAPI** se encargará de resolverlas.

## Primera dependencia "dependable" { #first-dependency-dependable }

Podrías crear una primera dependencia ("dependable") así:

{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[8:9] *}

### `app.dependency_overrides` 속성 사용하기

이런 경우를 위해 **FastAPI** 응용 프로그램에는 `app.dependency_overrides`라는 속성이 있습니다. 이는 간단한 `dict`입니다.

테스트를 위해 의존성을 오버라이드하려면, 원래 의존성(함수)을 키로 설정하고 오버라이드할 의존성(다른 함수)을 값으로 설정합니다.

그럼 **FastAPI**는 원래 의존성 대신 오버라이드된 의존성을 호출합니다.

{* ../../docs_src/dependency_testing/tutorial001_an_py310.py hl[26:27,30] *}

/// tip | 팁

**FastAPI** 애플리케이션 어디에서든 사용된 의존성에 대해 오버라이드를 설정할 수 있습니다.

from fastapi.testclient import TestClient

from docs_src.path_operation_advanced_configuration.tutorial006_py39 import app

client = TestClient(app)


def test_post():
    response = client.post("/items/", content=b"this is actually not validated")
    assert response.status_code == 200, response.text
    assert response.json() == {
        "size": 30,
        "content": {
            "name": "Maaaagic",
            "price": 42,

## Es testen { #check-it }

Jetzt wird jeder <abbr title="Request – Anfrage: Daten, die der Client zum Server sendet">Request</abbr> unter dem Pfad `/v1/` von der Flask-Anwendung verarbeitet.

Und der Rest wird von **FastAPI** gehandhabt.

# Запити з формами та файлами

У FastAPI Ви можете одночасно отримувати файли та поля форми, використовуючи `File` і `Form`.

/// info | Інформація

Щоб отримувати завантажені файли та/або дані форми, спочатку встановіть <a href="https://github.com/Kludex/python-multipart" class="external-link" target="_blank">python-multipart</a>.

from fastapi.testclient import TestClient

from docs_src.handling_errors.tutorial006_py39 import app

client = TestClient(app)


def test_get_validation_error():
    response = client.get("/items/foo")
    assert response.status_code == 422, response.text
    assert response.json() == {
        "detail": [
            {
                "type": "int_parsing",
                "loc": ["path", "item_id"],

from fastapi.testclient import TestClient

from docs_src.behind_a_proxy.tutorial001_py39 import app

client = TestClient(app, root_path="/api/v1")


def test_main():
    response = client.get("/app")
    assert response.status_code == 200
    assert response.json() == {"message": "Hello World", "root_path": "/api/v1"}


def test_openapi():
    response = client.get("/openapi.json")
    assert response.status_code == 200

from fastapi import FastAPI
from fastapi.openapi.docs import (
    get_redoc_html,
    get_swagger_ui_html,
    get_swagger_ui_oauth2_redirect_html,
)
from fastapi.staticfiles import StaticFiles

app = FastAPI(docs_url=None, redoc_url=None)

app.mount("/static", StaticFiles(directory="static"), name="static")


@app.get("/docs", include_in_schema=False)
async def custom_swagger_ui_html():
    return get_swagger_ui_html(

from typing import Annotated

import pytest
from fastapi import Depends, FastAPI, Security
from fastapi.testclient import TestClient


@pytest.fixture(name="call_counter")
def call_counter_fixture():
    return {"count": 0}


@pytest.fixture(name="app")
def app_fixture(call_counter: dict[str, int]):
    def get_db():
        call_counter["count"] += 1
        return f"db_{call_counter['count']}"

from fastapi import FastAPI
from fastapi.responses import PlainTextResponse

app = FastAPI()


@app.get("/", response_class=PlainTextResponse)
async def main():