🎚 🔢

👆 💪 🔬 🎚 🔢 🎏 🌌 👆 🔬 Query, Path & Cookie 🔢.

🗄 Header

🥇 🗄 Header:

Python 3.8+ - non-Annotated

from typing import Union

from fastapi import FastAPI, Header

app = FastAPI()


@app.get("/items/")
async def read_items(user_agent: Union[str, None] = Header(default=None)):
    return {"User-Agent": user_agent}

🤓 Other versions and variants

Python 3.10+Python 3.9+Python 3.8+Python 3.10+ - non-Annotated

from typing import Annotated

from fastapi import FastAPI, Header

app = FastAPI()


@app.get("/items/")
async def read_items(user_agent: Annotated[str | None, Header()] = None):
    return {"User-Agent": user_agent}

from typing import Annotated, Union

from fastapi import FastAPI, Header

app = FastAPI()


@app.get("/items/")
async def read_items(user_agent: Annotated[Union[str, None], Header()] = None):
    return {"User-Agent": user_agent}

from typing import Union

from fastapi import FastAPI, Header
from typing_extensions import Annotated

app = FastAPI()


@app.get("/items/")
async def read_items(user_agent: Annotated[Union[str, None], Header()] = None):
    return {"User-Agent": user_agent}

Tip

Prefer to use the Annotated version if possible.

from fastapi import FastAPI, Header

app = FastAPI()


@app.get("/items/")
async def read_items(user_agent: str | None = Header(default=None)):
    return {"User-Agent": user_agent}

📣 Header 🔢

⤴️ 📣 🎚 🔢 ⚙️ 🎏 📊 ⏮️ Path, Query & Cookie.

🥇 💲 🔢 💲, 👆 💪 🚶‍♀️ 🌐 ➕ 🔬 ⚖️ ✍ 🔢:

Python 3.8+ - non-Annotated

from typing import Union

from fastapi import FastAPI, Header

app = FastAPI()


@app.get("/items/")
async def read_items(user_agent: Union[str, None] = Header(default=None)):
    return {"User-Agent": user_agent}

🤓 Other versions and variants

Python 3.10+Python 3.9+Python 3.8+Python 3.10+ - non-Annotated

from typing import Annotated

from fastapi import FastAPI, Header

app = FastAPI()


@app.get("/items/")
async def read_items(user_agent: Annotated[str | None, Header()] = None):
    return {"User-Agent": user_agent}

from typing import Annotated, Union

from fastapi import FastAPI, Header

app = FastAPI()


@app.get("/items/")
async def read_items(user_agent: Annotated[Union[str, None], Header()] = None):
    return {"User-Agent": user_agent}

from typing import Union

from fastapi import FastAPI, Header
from typing_extensions import Annotated

app = FastAPI()


@app.get("/items/")
async def read_items(user_agent: Annotated[Union[str, None], Header()] = None):
    return {"User-Agent": user_agent}

Tip

Prefer to use the Annotated version if possible.

from fastapi import FastAPI, Header

app = FastAPI()


@app.get("/items/")
async def read_items(user_agent: str | None = Header(default=None)):
    return {"User-Agent": user_agent}

📡 ℹ

Header "👭" 🎓 Path, Query & Cookie. ⚫️ 😖 ⚪️➡️ 🎏 ⚠ Param 🎓.

✋️ 💭 👈 🕐❔ 👆 🗄 Query, Path, Header, & 🎏 ⚪️➡️ fastapi, 👈 🤙 🔢 👈 📨 🎁 🎓.

Info

📣 🎚, 👆 💪 ⚙️ Header, ↩️ ⏪ 🔢 🔜 🔬 🔢 🔢.

🏧 🛠️

Header ✔️ 🐥 ➕ 🛠️ 🔛 🔝 ⚫️❔ Path, Query & Cookie 🚚.

🌅 🐩 🎚 🎏 "🔠" 🦹, 💭 "➖ 🔣" (-).

✋️ 🔢 💖 user-agent ❌ 🐍.

, 🔢, Header 🔜 🗜 🔢 📛 🦹 ⚪️➡️ 🎦 (_) 🔠 (-) ⚗ & 📄 🎚.

, 🇺🇸🔍 🎚 💼-😛,, 👆 💪 📣 👫 ⏮️ 🐩 🐍 👗 (💭 "🔡").

, 👆 💪 ⚙️ user_agent 👆 🛎 🔜 🐍 📟, ↩️ 💆‍♂ 🎯 🥇 🔤 User_Agent ⚖️ 🕳 🎏.

🚥 🤔 👆 💪 ❎ 🏧 🛠️ 🎦 🔠, ⚒ 🔢 convert_underscores Header False:

Python 3.8+ - non-Annotated

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),
):
    return {"strange_header": strange_header}

🤓 Other versions and variants

Python 3.10+Python 3.9+Python 3.8+Python 3.10+ - non-Annotated

from typing import Annotated

from fastapi import FastAPI, Header

app = FastAPI()


@app.get("/items/")
async def read_items(
    strange_header: Annotated[str | None, Header(convert_underscores=False)] = None,
):
    return {"strange_header": strange_header}

from typing import Annotated, Union

from fastapi import FastAPI, Header

app = FastAPI()


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

from typing import Union

from fastapi import FastAPI, Header
from typing_extensions import Annotated

app = FastAPI()


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

Tip

Prefer to use the Annotated version if possible.

from fastapi import FastAPI, Header

app = FastAPI()


@app.get("/items/")
async def read_items(
    strange_header: str | None = Header(default=None, convert_underscores=False),
):
    return {"strange_header": strange_header}

Warning

⏭ ⚒ convert_underscores False, 🐻 🤯 👈 🇺🇸🔍 🗳 & 💽 / ⚙️ 🎚 ⏮️ 🎦.

❎ 🎚

⚫️ 💪 📨 ❎ 🎚. 👈 ⛓, 🎏 🎚 ⏮️ 💗 💲.

👆 💪 🔬 👈 💼 ⚙️ 📇 🆎 📄.

👆 🔜 📨 🌐 💲 ⚪️➡️ ❎ 🎚 🐍 list.

🖼, 📣 🎚 X-Token 👈 💪 😑 🌅 🌘 🕐, 👆 💪 ✍:

Python 3.8+ - non-Annotated

from typing import List, Union

from fastapi import FastAPI, Header

app = FastAPI()


@app.get("/items/")
async def read_items(x_token: Union[List[str], None] = Header(default=None)):
    return {"X-Token values": x_token}

🤓 Other versions and variants

Python 3.10+Python 3.9+Python 3.8+Python 3.10+ - non-AnnotatedPython 3.9+ - non-Annotated

from typing import Annotated

from fastapi import FastAPI, Header

app = FastAPI()


@app.get("/items/")
async def read_items(x_token: Annotated[list[str] | None, Header()] = None):
    return {"X-Token values": x_token}

from typing import Annotated, List, Union

from fastapi import FastAPI, Header

app = FastAPI()


@app.get("/items/")
async def read_items(x_token: Annotated[Union[List[str], None], Header()] = None):
    return {"X-Token values": x_token}

from typing import List, Union

from fastapi import FastAPI, Header
from typing_extensions import Annotated

app = FastAPI()


@app.get("/items/")
async def read_items(x_token: Annotated[Union[List[str], None], Header()] = None):
    return {"X-Token values": x_token}

Tip

Prefer to use the Annotated version if possible.

from fastapi import FastAPI, Header

app = FastAPI()


@app.get("/items/")
async def read_items(x_token: list[str] | None = Header(default=None)):
    return {"X-Token values": x_token}

Tip

Prefer to use the Annotated version if possible.

from typing import Union

from fastapi import FastAPI, Header

app = FastAPI()


@app.get("/items/")
async def read_items(x_token: Union[list[str], None] = Header(default=None)):
    return {"X-Token values": x_token}

🚥 👆 🔗 ⏮️ 👈 ➡ 🛠️ 📨 2️⃣ 🇺🇸🔍 🎚 💖:

X-Token: foo
X-Token: bar

📨 🔜 💖:

{
    "X-Token values": [
        "bar",
        "foo"
    ]
}

🌃

📣 🎚 ⏮️ Header, ⚙️ 🎏 ⚠ ⚓ Query, Path & Cookie.

& 🚫 😟 🔃 🎦 👆 🔢, FastAPI 🔜 ✊ 💅 🏭 👫.