from typing import Optional

from fastapi import Depends, FastAPI, Security
from fastapi.security import APIKeyCookie
from fastapi.testclient import TestClient
from pydantic import BaseModel

app = FastAPI()

api_key = APIKeyCookie(name="key", auto_error=False)


class User(BaseModel):
    username: str


def get_current_user(oauth_header: Optional[str] = Security(api_key)):
    if oauth_header is None:
        return None

from typing import Optional

from fastapi import FastAPI
from pydantic import BaseModel


class Item(BaseModel):
    name: str
    description: Optional[str] = None


app = FastAPI()


@app.post("/items/")
def create_item(item: Item):
    return item


@app.get("/items/")
def read_items() -> list[Item]:
    return [
        Item(
            name="Portal Gun",

        with:
          results_file: results.sarif
          results_format: sarif
          publish_results: true

      # Upload the results as artifacts (optional). Commenting out will disable uploads of run results in SARIF
      # format to the repository Actions tab.
      - name: "Upload artifact"
        uses: actions/upload-artifact@50769540e7f4bd5e21e526ee35c689e35e0d6874 # v4.4.0

			Type:        "on|off",
			Description: "set to enable callhome" + defaultHelpPostfix(Enable),
			Optional:    true,
		},
		config.HelpKV{
			Key:         Frequency,
			Type:        "duration",
			Description: "time duration between callhome cycles e.g. 24h" + defaultHelpPostfix(Frequency),
			Optional:    true,
		},
	}

So:

```Python
q: Union[str, None] = Query(default=None)
```

...makes the parameter optional, with a default value of `None`, the same as:

```Python
q: Union[str, None] = None
```

And in Python 3.10 and above:

```Python
q: str | None = Query(default=None)
```

...makes the parameter optional, with a default value of `None`, the same as:

```Python
q: str | None = None
```

from typing import Optional, Union

from dirty_equals import IsDict
from fastapi import FastAPI
from fastapi.testclient import TestClient
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: Optional[str] = None


class ExtendedItem(Item):
    age: int


@app.post("/items/")
def save_union_different_body(item: Union[ExtendedItem, Item]):
    return {"item": item}

### Kompakt

Es gibt für alles sensible **Defaultwerte**, mit optionaler Konfiguration überall. Alle Parameter können feinjustiert werden, damit sie tun, was Sie benötigen, und die API definieren, die Sie brauchen.

Aber standardmäßig **„funktioniert einfach alles“**.

### Validierung

from typing import Optional

from fastapi import Depends, FastAPI
from pydantic import BaseModel, validator

app = FastAPI()


class ModelB(BaseModel):
    username: str


class ModelC(ModelB):
    password: str


class ModelA(BaseModel):
    name: str
    description: Optional[str] = None
    model_b: ModelB

    @validator("name")
    def lower_username(cls, name: str, values):

			Description: "[DEPRECATED] authorization token for OPA endpoint" + defaultHelpPostfix(AuthToken),
			Optional:    true,
			Type:        "string",
			Sensitive:   true,
			Secret:      true,
		},
		config.HelpKV{
			Key:         config.Comment,
			Description: config.DefaultComment,
			Optional:    true,
			Type:        "sentence",
		},
	}

  scheme: http
  static_configs:
  - targets: ['localhost:9000']
```

##### Node centric (optional)

```yaml
- job_name: minio-job-node
  bearer_token: <secret>
  metrics_path: /minio/v2/metrics/node
  scheme: http
  static_configs:
  - targets: ['localhost:9000']
```

##### Resource centric (optional)

```yaml
- job_name: minio-job-resource
  bearer_token: <secret>