// Da wir die Umgebungsvariable nicht gesetzt haben, erhalten wir den Defaultwert

Hello World from Python

// Aber wenn wir zuerst eine Umgebungsvariable erstellen
$ export MY_NAME="Wade Wilson"

// Und dann das Programm erneut aufrufen
$ python main.py

// Jetzt kann es die Umgebungsvariable lesen

Hello Wade Wilson from Python
```

</div>

////

//// tab | Windows PowerShell

# `FastAPI` class

Here's the reference information for the `FastAPI` class, with all its parameters, attributes and methods.

You can import the `FastAPI` class directly from `fastapi`:

```python
from fastapi import FastAPI
```

::: fastapi.FastAPI
    options:
        members:
            - openapi_version
            - webhooks
            - state
            - dependency_overrides
            - openapi

from typing import Annotated

from fastapi import FastAPI, File, UploadFile

app = FastAPI()


@app.post("/files/")
async def create_file(file: Annotated[bytes, File(description="A file read as bytes")]):
    return {"file_size": len(file)}


@app.post("/uploadfile/")
async def create_upload_file(
    file: Annotated[UploadFile, File(description="A file read as UploadFile")],
):

     *
     * @return the context class loader
     */
    public static ClassLoader getClassLoader() {
        return Thread.currentThread().getContextClassLoader();
    }

    /**
     * Returns the resource from the context class loader.
     *
     * @param path
     *            The resource path. Must not be {@literal null} or empty string.
     * @return The resource {@link URL}
     * @see #getResource(String, String)
     */

}

plugins.withType<IdeaPlugin> {
    configure<IdeaModel> {
        module {
            val testFixtures = sourceSets.testFixtures.get()
            testSources.from(testFixtures.java.srcDirs)
            testSources.from(testFixtures.groovy.srcDirs)
            testResources.from(testFixtures.resources.srcDirs)
        }
    }

/**
 * Represents a Kerberos AP-REQ (Application Request) message.
 * This class parses and contains the authentication request sent from a client to a server.
 */
public class KerberosApRequest {

    private byte apOptions;
    private KerberosTicket ticket;

    /**
     * Creates a Kerberos AP request from a token.
     *
     * @param token the Kerberos AP-REQ token
     * @param keys the Kerberos keys for decryption

from typing import Union

from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    description: Union[str, None] = None
    price: float
    tax: Union[float, None] = None
    tags: set[str] = set()


@app.post("/items/", response_model=Item, summary="Create an item")
async def create_item(item: Item):
    """
    Create an item with all the information:

import pytest
from fastapi import APIRouter, FastAPI
from fastapi.exceptions import FastAPIError
from fastapi.testclient import TestClient

app = FastAPI()

router = APIRouter()


@router.get("")
def get_empty():
    return ["OK"]


app.include_router(router, prefix="/prefix")


client = TestClient(app)


def test_use_empty():
    with client:
        response = client.get("/prefix")

from typing import Union

from fastapi import Body, FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    description: Union[str, None] = None
    price: float
    tax: Union[float, None] = None


@app.put("/items/{item_id}")
async def update_item(
    *,
    item_id: int,
    item: Item = Body(
        examples=[
            {
                "name": "Foo",

from typing import Union

from fastapi import Body, FastAPI
from pydantic import BaseModel, Field

app = FastAPI()


class Item(BaseModel):
    name: str
    description: Union[str, None] = Field(
        default=None, title="The description of the item", max_length=300
    )
    price: float = Field(gt=0, description="The price must be greater than zero")
    tax: Union[float, None] = None


@app.put("/items/{item_id}")