# build configuration. You must set the following variables to control this
# script:
#
#   TF_BISECT_GOOD: Last known good commit (e.g. commit from the last passing job)
#   TF_BISECT_BAD: First bad commit (e.g. commit from the first failing job)
#   TF_BISECT_SCRIPT: The build script path relative to the TF root dir, e.g.
#     ci/official/wheel.sh
#   TFCI: The env config path, relative to the TF root dir, e.g.

from fastapi import FastAPI, Header
from pydantic import BaseModel

app = FastAPI()


class CommonHeaders(BaseModel):
    model_config = {"extra": "forbid"}

    host: str
    save_data: bool
    if_modified_since: str | None = None
    traceparent: str | None = None
    x_tag: list[str] = []


@app.get("/items/")
async def read_items(headers: CommonHeaders = Header()):

<div class="termy">

```console
// 這裡我們還沒有設定環境變數
$ python main.py

// 因為我們沒有設定環境變數，所以我們得到的是預設值

Hello World from Python

// 但是如果我們事先建立過一個環境變數
$ export MY_NAME="Wade Wilson"

// 然後再次呼叫程式
$ python main.py

// 現在就可以讀取到環境變數了

Hello Wade Wilson from Python
```

</div>

////

//// tab | Windows PowerShell

<div class="termy">

```console

from fastapi import FastAPI
from fastapi.responses import FileResponse

some_file_path = "large-video-file.mp4"
app = FastAPI()


@app.get("/")
async def main():

    protected int parameterCount;
    /** Offset from the start of the SMB header to the parameter bytes */
    protected int parameterOffset;
    /** Displacement of these parameter bytes from the start of the total parameter block */
    protected int parameterDisplacement;
    /** Number of data bytes being sent in this request */
    protected int dataCount;
    /** Offset from the start of the SMB header to the data bytes */

 * {@link #compareAndSet} by comparing their bitwise representation using {@link
 * Double#doubleToRawLongBits}, which differs from both the primitive double {@code ==} operator and
 * from {@link Double#equals}, as if implemented by:
 *
 * {@snippet :
 * static boolean bitEquals(double x, double y) {
 *   long xBits = Double.doubleToRawLongBits(x);

  <span style="background-color:#009485"><font color="#D3D7CF"> FastAPI </font></span>  Starting development server 🚀

             Searching for package file structure from directories with
             <font color="#3465A4">__init__.py</font> files
             Importing from <font color="#75507B">/home/user/code/</font><font color="#AD7FA8">awesomeapp</font>

from typing import Annotated

import pytest
from dirty_equals import IsOneOf, IsPartialDict
from fastapi import Body, FastAPI
from fastapi.testclient import TestClient
from pydantic import BaseModel, Field

from .utils import get_body_model_name

app = FastAPI()

# =====================================================================================
# Without aliases


@app.post("/required-list-str", operation_id="required_list_str")

You can use the `Jinja2Templates` class to render Jinja templates.

Read more about it in the [FastAPI docs for Templates](https://fastapi.tiangolo.com/advanced/templates/).

You can import it directly from `fastapi.templating`:

```python
from fastapi.templating import Jinja2Templates
```

from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware

app = FastAPI()

origins = [
    "http://localhost.tiangolo.com",
    "https://localhost.tiangolo.com",
    "http://localhost",
    "http://localhost:8080",
]

app.add_middleware(
    CORSMiddleware,
    allow_origins=origins,
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)


@app.get("/")