// TODO: https://github.com/istio/istio/issues/41937
		grpc.WithTransportCredentials(credentials.NewTLS(
			&tls.Config{
				// Always skip verifying, because without it we always get "certificate signed by unknown authority".
				// We don't set the XDSSAN for the same reason.
				InsecureSkipVerify: true,
			})),
		grpc.WithPerRPCCredentials(k8sCreds),
	}, nil

from datetime import datetime
from typing import Union

from pydantic import BaseModel


class User(BaseModel):
    id: int
    name: str = "John Doe"
    signup_ts: Union[datetime, None] = None
    friends: list[int] = []


external_data = {
    "id": "123",
    "signup_ts": "2017-06-01 12:22",
    "friends": [1, "2", b"3"],
}
user = User(**external_data)
print(user)

from typing import List, Union

from fastapi import FastAPI
from pydantic import BaseModel


class Item(BaseModel):
    name: str
    description: Union[str, None] = 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",

from typing import Union


def say_hi(name: Union[str, None] = None):
    if name is not None:
        print(f"Hey {name}!")
    else:

		setCopy[k] = v
	}
	return setCopy
}

// add - adds TargetID to the set.
func (set TargetIDSet) add(targetID TargetID) {
	set[targetID] = struct{}{}
}

// Union - returns union with given set as new set.
func (set TargetIDSet) Union(sset TargetIDSet) TargetIDSet {
	nset := set.Clone()

	for k := range sset {
		nset.add(k)
	}

	return nset
}

from typing import Union

from fastapi import FastAPI, Query
from typing_extensions import Annotated

app = FastAPI()


@app.get("/items/")
async def read_items(
    q: Annotated[
        Union[str, None],
        Query(
            title="Query string",
            description="Query string for the items to search in the database that have a good match",
            min_length=3,
        ),
    ] = None,
):

		}
	case fm&fs.ModeNamedPipe != 0:
		h.Typeflag = TypeFifo
	case fm&fs.ModeSocket != 0:
		return nil, fmt.Errorf("archive/tar: sockets not supported")
	default:
		return nil, fmt.Errorf("archive/tar: unknown file mode %v", fm)
	}
	if fm&fs.ModeSetuid != 0 {
		h.Mode |= c_ISUID
	}
	if fm&fs.ModeSetgid != 0 {
		h.Mode |= c_ISGID
	}
	if fm&fs.ModeSticky != 0 {
		h.Mode |= c_ISVTX
	}

```

////

#### Using `Union` or `Optional`

If you are using a Python version below 3.10, here's a tip from my very **subjective** point of view:

* 🚨 Avoid using `Optional[SomeType]`
* Instead ✨ **use `Union[SomeType, None]`** ✨.

from typing import Union

from fastapi import FastAPI, Header

app = FastAPI()


@app.get("/items/")
async def read_items(
    strange_header: Union[str, None] = Header(default=None, convert_underscores=False),
):

from datetime import datetime
from typing import Union

from fastapi import FastAPI
from fastapi.encoders import jsonable_encoder
from fastapi.responses import JSONResponse
from pydantic import BaseModel


class Item(BaseModel):
    title: str
    timestamp: datetime
    description: Union[str, None] = None


app = FastAPI()


@app.put("/items/{id}")
def update_item(id: str, item: Item):