from fastapi import Depends, FastAPI

app = FastAPI()


class FixedContentQueryChecker:
    def __init__(self, fixed_content: str):
        self.fixed_content = fixed_content

    def __call__(self, q: str = ""):
        if q:
            return self.fixed_content in q
        return False


checker = FixedContentQueryChecker("bar")


@app.get("/query-checker/")

from fastapi import FastAPI, Request
from fastapi.responses import JSONResponse


class UnicornException(Exception):
    def __init__(self, name: str):
        self.name = name


app = FastAPI()


@app.exception_handler(UnicornException)
async def unicorn_exception_handler(request: Request, exc: UnicornException):
    return JSONResponse(
        status_code=418,

from typing import Annotated

from fastapi import Depends, FastAPI

app = FastAPI()


fake_items_db = [{"item_name": "Foo"}, {"item_name": "Bar"}, {"item_name": "Baz"}]


class CommonQueryParams:
    def __init__(self, q: str | None = None, skip: int = 0, limit: int = 100):
        self.q = q
        self.skip = skip
        self.limit = limit


@app.get("/items/")

Nehmen wir an, Sie haben eine Dateistruktur wie diese:

```
.
├── app
│   ├── __init__.py
│   ├── main.py
│   ├── dependencies.py
│   └── routers
│   │   ├── __init__.py
│   │   ├── items.py
│   │   └── users.py
│   └── internal
│       ├── __init__.py
│       └── admin.py
```

/// tip | "Tipp"

Es gibt mehrere `__init__.py`-Dateien: eine in jedem Verzeichnis oder Unterverzeichnis.

from fastapi import Depends, FastAPI
from typing_extensions import Annotated

app = FastAPI()


fake_items_db = [{"item_name": "Foo"}, {"item_name": "Bar"}, {"item_name": "Baz"}]


class CommonQueryParams:
    def __init__(self, q: Union[str, None] = None, skip: int = 0, limit: int = 100):
        self.q = q
        self.skip = skip
        self.limit = limit


@app.get("/items/")

db_state = ContextVar("db_state", default=db_state_default.copy())


class PeeweeConnectionState(peewee._ConnectionState):
    def __init__(self, **kwargs):
        super().__setattr__("_state", db_state)
        super().__init__(**kwargs)

    def __setattr__(self, name, value):
        self._state.get()[name] = value

    def __getattr__(self, name):
        return self._state.get()[name]

Digamos que você tenha uma estrutura de arquivos como esta:

```
.
├── app
│   ├── __init__.py
│   ├── main.py
│   ├── dependencies.py
│   └── routers
│   │   ├── __init__.py
│   │   ├── items.py
│   │   └── users.py
│   └── internal
│       ├── __init__.py
│       └── admin.py
```

/// tip | "Dica"

Existem vários arquivos `__init__.py` presentes em cada diretório ou subdiretório.

```
.
├── app
│   ├── __init__.py
│   └── main.py
```

📁 `main.py` 👆 ✔️ 👆 **FastAPI** 📱:


```Python
{!../../docs_src/app_testing/main.py!}
```

### 🔬 📁

⤴️ 👆 💪 ✔️ 📁 `test_main.py` ⏮️ 👆 💯. ⚫️ 💪 🖖 🔛 🎏 🐍 📦 (🎏 📁 ⏮️ `__init__.py` 📁):

``` hl_lines="5"
.
├── app
│   ├── __init__.py
│   ├── main.py
│   └── test_main.py
```

class MySuperContextManager:
    def __init__(self):
        self.db = DBSession()

    def __enter__(self):
        return self.db

    def __exit__(self, exc_type, exc_value, traceback):
        self.db.close()


async def get_db():
    with MySuperContextManager() as db:

```
.
├── app
│   ├── __init__.py
│   └── main.py
```

In der Datei `main.py` haben Sie Ihre **FastAPI**-Anwendung:


```Python
{!../../docs_src/app_testing/main.py!}
```

### Testdatei

Dann könnten Sie eine Datei `test_main.py` mit Ihren Tests haben. Sie könnte sich im selben Python-Package befinden (dasselbe Verzeichnis mit einer `__init__.py`-Datei):

``` hl_lines="5"
.
├── app