Header-Parameter-Modelle¶
Wenn Sie eine Gruppe verwandter Header-Parameter haben, können Sie ein Pydantic-Modell erstellen, um diese zu deklarieren.
Dadurch können Sie das Modell an mehreren Stellen wiederverwenden und auch Validierungen und Metadaten für alle Parameter gleichzeitig deklarieren. 😎
Hinweis
Dies wird seit FastAPI Version 0.115.0 unterstützt. 🤓
Header-Parameter mit einem Pydantic-Modell¶
Deklarieren Sie die erforderlichen Header-Parameter in einem Pydantic-Modell und dann den Parameter als Header:
from typing import Annotated
from fastapi import FastAPI, Header
from pydantic import BaseModel
app = FastAPI()
class CommonHeaders(BaseModel):
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: Annotated[CommonHeaders, Header()]):
return headers
🤓 Other versions and variants
from typing import Annotated, Union
from fastapi import FastAPI, Header
from pydantic import BaseModel
app = FastAPI()
class CommonHeaders(BaseModel):
host: str
save_data: bool
if_modified_since: Union[str, None] = None
traceparent: Union[str, None] = None
x_tag: list[str] = []
@app.get("/items/")
async def read_items(headers: Annotated[CommonHeaders, Header()]):
return headers
from typing import List, Union
from fastapi import FastAPI, Header
from pydantic import BaseModel
from typing_extensions import Annotated
app = FastAPI()
class CommonHeaders(BaseModel):
host: str
save_data: bool
if_modified_since: Union[str, None] = None
traceparent: Union[str, None] = None
x_tag: List[str] = []
@app.get("/items/")
async def read_items(headers: Annotated[CommonHeaders, Header()]):
return headers
Tip
Prefer to use the Annotated version if possible.
from fastapi import FastAPI, Header
from pydantic import BaseModel
app = FastAPI()
class CommonHeaders(BaseModel):
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()):
return headers
Tip
Prefer to use the Annotated version if possible.
from typing import Union
from fastapi import FastAPI, Header
from pydantic import BaseModel
app = FastAPI()
class CommonHeaders(BaseModel):
host: str
save_data: bool
if_modified_since: Union[str, None] = None
traceparent: Union[str, None] = None
x_tag: list[str] = []
@app.get("/items/")
async def read_items(headers: CommonHeaders = Header()):
return headers
Tip
Prefer to use the Annotated version if possible.
from typing import List, Union
from fastapi import FastAPI, Header
from pydantic import BaseModel
app = FastAPI()
class CommonHeaders(BaseModel):
host: str
save_data: bool
if_modified_since: Union[str, None] = None
traceparent: Union[str, None] = None
x_tag: List[str] = []
@app.get("/items/")
async def read_items(headers: CommonHeaders = Header()):
return headers
FastAPI wird die Daten für jedes Feld aus den Headern des Request extrahieren und Ihnen das von Ihnen definierte Pydantic-Modell geben.
Die Dokumentation testen¶
Sie können die erforderlichen Header in der Dokumentationsoberfläche unter /docs sehen:
Zusätzliche Header verbieten¶
In einigen speziellen Anwendungsfällen (wahrscheinlich nicht sehr häufig) möchten Sie möglicherweise die Header einschränken, die Sie erhalten möchten.
Sie können Pydantics Modellkonfiguration verwenden, um extra Felder zu verbieten (forbid):
from typing import Annotated
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: Annotated[CommonHeaders, Header()]):
return headers
🤓 Other versions and variants
from typing import Annotated, Union
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: Union[str, None] = None
traceparent: Union[str, None] = None
x_tag: list[str] = []
@app.get("/items/")
async def read_items(headers: Annotated[CommonHeaders, Header()]):
return headers
from typing import List, Union
from fastapi import FastAPI, Header
from pydantic import BaseModel
from typing_extensions import Annotated
app = FastAPI()
class CommonHeaders(BaseModel):
model_config = {"extra": "forbid"}
host: str
save_data: bool
if_modified_since: Union[str, None] = None
traceparent: Union[str, None] = None
x_tag: List[str] = []
@app.get("/items/")
async def read_items(headers: Annotated[CommonHeaders, Header()]):
return headers
Tip
Prefer to use the Annotated version if possible.
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()):
return headers
Tip
Prefer to use the Annotated version if possible.
from typing import Union
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: Union[str, None] = None
traceparent: Union[str, None] = None
x_tag: list[str] = []
@app.get("/items/")
async def read_items(headers: CommonHeaders = Header()):
return headers
Tip
Prefer to use the Annotated version if possible.
from typing import List, Union
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: Union[str, None] = None
traceparent: Union[str, None] = None
x_tag: List[str] = []
@app.get("/items/")
async def read_items(headers: CommonHeaders = Header()):
return headers
Wenn ein Client versucht, einige zusätzliche Header zu senden, erhält er eine Error-Response.
Zum Beispiel, wenn der Client versucht, einen tool-Header mit einem Wert von plumbus zu senden, erhält er eine Error-Response, die ihm mitteilt, dass der Header-Parameter tool nicht erlaubt ist:
{
"detail": [
{
"type": "extra_forbidden",
"loc": ["header", "tool"],
"msg": "Extra inputs are not permitted",
"input": "plumbus",
}
]
}
Automatische Umwandlung von Unterstrichen deaktivieren¶
Ähnlich wie bei regulären Header-Parametern werden bei der Verwendung von Unterstrichen in den Parameternamen diese automatisch in Bindestriche umgewandelt.
Wenn Sie beispielsweise einen Header-Parameter save_data im Code haben, wird der erwartete HTTP-Header save-data sein, und er wird auch so in der Dokumentation angezeigt.
Falls Sie aus irgendeinem Grund diese automatische Umwandlung deaktivieren müssen, können Sie dies auch für Pydantic-Modelle für Header-Parameter tun.
from typing import Annotated
from fastapi import FastAPI, Header
from pydantic import BaseModel
app = FastAPI()
class CommonHeaders(BaseModel):
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: Annotated[CommonHeaders, Header(convert_underscores=False)],
):
return headers
🤓 Other versions and variants
from typing import Annotated, Union
from fastapi import FastAPI, Header
from pydantic import BaseModel
app = FastAPI()
class CommonHeaders(BaseModel):
host: str
save_data: bool
if_modified_since: Union[str, None] = None
traceparent: Union[str, None] = None
x_tag: list[str] = []
@app.get("/items/")
async def read_items(
headers: Annotated[CommonHeaders, Header(convert_underscores=False)],
):
return headers
from typing import List, Union
from fastapi import FastAPI, Header
from pydantic import BaseModel
from typing_extensions import Annotated
app = FastAPI()
class CommonHeaders(BaseModel):
host: str
save_data: bool
if_modified_since: Union[str, None] = None
traceparent: Union[str, None] = None
x_tag: List[str] = []
@app.get("/items/")
async def read_items(
headers: Annotated[CommonHeaders, Header(convert_underscores=False)],
):
return headers
Tip
Prefer to use the Annotated version if possible.
from fastapi import FastAPI, Header
from pydantic import BaseModel
app = FastAPI()
class CommonHeaders(BaseModel):
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(convert_underscores=False)):
return headers
Tip
Prefer to use the Annotated version if possible.
from typing import Union
from fastapi import FastAPI, Header
from pydantic import BaseModel
app = FastAPI()
class CommonHeaders(BaseModel):
host: str
save_data: bool
if_modified_since: Union[str, None] = None
traceparent: Union[str, None] = None
x_tag: list[str] = []
@app.get("/items/")
async def read_items(headers: CommonHeaders = Header(convert_underscores=False)):
return headers
Tip
Prefer to use the Annotated version if possible.
from typing import List, Union
from fastapi import FastAPI, Header
from pydantic import BaseModel
app = FastAPI()
class CommonHeaders(BaseModel):
host: str
save_data: bool
if_modified_since: Union[str, None] = None
traceparent: Union[str, None] = None
x_tag: List[str] = []
@app.get("/items/")
async def read_items(headers: CommonHeaders = Header(convert_underscores=False)):
return headers
Achtung
Bevor Sie convert_underscores auf False setzen, bedenken Sie, dass einige HTTP-Proxies und -Server die Verwendung von Headern mit Unterstrichen nicht zulassen.
Zusammenfassung¶
Sie können Pydantic-Modelle verwenden, um Header in FastAPI zu deklarieren. 😎