FastAPI - Pydantic - 值错误引发内部服务器错误
FastAPI - Pydantic - Value Error Raises Internal Server Error
我在 Pydantic 中使用 FastAPI。
我的问题 - 我需要使用 Pydantic
引发 ValueError
from fastapi import FastAPI
from pydantic import BaseModel, validator
from fastapi import Depends, HTTPException
app = FastAPI()
class RankInput(BaseModel):
rank: int
@validator('rank')
def check_if_value_in_range(cls, v):
"""
check if input rank is within range
"""
if not 0 < v < 1000001:
raise ValueError("Rank Value Must be within range (0,1000000)")
#raise HTTPException(status_code=400, detail="Rank Value Error") - this works But I am looking for a solution using ValueError
return v
def get_info_by_rank(rank):
return rank
@app.get('/rank/{rank}')
async def get_rank(value: RankInput = Depends()):
result = get_info_by_rank(value.rank)
return result
这段代码在引发 ValueError 时给出 Internal Server Error
INFO: 127.0.0.1:59427 - "GET /info/?rank=-1 HTTP/1.1" 500 Internal Server Error
ERROR: Exception in ASGI application
Traceback (most recent call last):
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/uvicorn/protocols/http/h11_impl.py", line 396, in run_asgi
result = await app(self.scope, self.receive, self.send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/uvicorn/middleware/proxy_headers.py", line 45, in __call__
return await self.app(scope, receive, send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/fastapi/applications.py", line 199, in __call__
await super().__call__(scope, receive, send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/applications.py", line 111, in __call__
await self.middleware_stack(scope, receive, send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/middleware/errors.py", line 181, in __call__
raise exc from None
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/middleware/errors.py", line 159, in __call__
await self.app(scope, receive, _send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/exceptions.py", line 82, in __call__
raise exc from None
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/exceptions.py", line 71, in __call__
await self.app(scope, receive, sender)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/routing.py", line 566, in __call__
await route.handle(scope, receive, send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/routing.py", line 227, in handle
await self.app(scope, receive, send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/routing.py", line 41, in app
response = await func(request)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/fastapi/routing.py", line 195, in app
dependency_overrides_provider=dependency_overrides_provider,
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/fastapi/dependencies/utils.py", line 550, in solve_dependencies
solved = await run_in_threadpool(call, **sub_values)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/concurrency.py", line 34, in run_in_threadpool
return await loop.run_in_executor(None, func, *args)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/concurrent/futures/thread.py", line 57, in run
result = self.fn(*self.args, **self.kwargs)
File "pydantic/main.py", line 400, in pydantic.main.BaseModel.__init__
pydantic.error_wrappers.ValidationError: 1 validation error for GetInput
rank
ValueError() takes no keyword arguments (type=type_error)
ERROR:uvicorn.error:Exception in ASGI application
Traceback (most recent call last):
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/uvicorn/protocols/http/h11_impl.py", line 396, in run_asgi
result = await app(self.scope, self.receive, self.send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/uvicorn/middleware/proxy_headers.py", line 45, in __call__
return await self.app(scope, receive, send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/fastapi/applications.py", line 199, in __call__
await super().__call__(scope, receive, send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/applications.py", line 111, in __call__
await self.middleware_stack(scope, receive, send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/middleware/errors.py", line 181, in __call__
raise exc from None
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/middleware/errors.py", line 159, in __call__
await self.app(scope, receive, _send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/exceptions.py", line 82, in __call__
raise exc from None
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/exceptions.py", line 71, in __call__
await self.app(scope, receive, sender)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/routing.py", line 566, in __call__
await route.handle(scope, receive, send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/routing.py", line 227, in handle
await self.app(scope, receive, send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/routing.py", line 41, in app
response = await func(request)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/fastapi/routing.py", line 195, in app
dependency_overrides_provider=dependency_overrides_provider,
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/fastapi/dependencies/utils.py", line 550, in solve_dependencies
solved = await run_in_threadpool(call, **sub_values)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/concurrency.py", line 34, in run_in_threadpool
return await loop.run_in_executor(None, func, *args)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/concurrent/futures/thread.py", line 57, in run
result = self.fn(*self.args, **self.kwargs)
File "pydantic/main.py", line 400, in pydantic.main.BaseModel.__init__
pydantic.error_wrappers.ValidationError: 1 validation error for GetInput
rank
ValueError() takes no keyword arguments (type=type_error)
我也检查了https://github.com/tiangolo/fastapi/issues/2180。
但是我想不出解决办法。
我需要做的是使用自定义状态代码提升 ValueError。
注意 - 我知道我可以通过提高 HTTPException 来完成工作。
但我正在寻找使用 ValueError
的解决方案
你能告诉我哪里错了吗？
还在 Github 上发布了此问题 - https://github.com/tiangolo/fastapi/issues/3761
如果您没有引发 HTTPException，那么通常任何其他未捕获的异常都会生成 500 响应（Internal Server Error）。如果您的意图是在引发特定异常时使用其他一些自定义错误消息和 HTTP 状态进行响应 - 例如 ValueError - 那么您可以使用向您的应用程序添加一个全局异常处理程序：
from fastapi import FastAPI, Request
from fastapi.responses import JSONResponse
@app.exception_handler(ValueError)
async def value_error_exception_handler(request: Request, exc: ValueError):
return JSONResponse(
status_code=400,
content={"message": str(exc)},
)
这将给出 400 响应（或者您可以将状态代码更改为您喜欢的任何内容），如下所示：
{
"message": "Value Must be within range (0,1000000)"
}
请注意，pydantic 期望验证者提出 ValueError、TypeError 或 AssertionError（参见 docs）pydantic将转换为 ValidationError.
此外，根据 FastAPI's documentation：
When a request contains invalid data, FastAPI internally raises a RequestValidationError.
RequestValidationError is a sub-class of Pydantic's ValidationError.
这样做的结果是 pydantic 模型验证期间出现的标准 Validation 错误将被转换为 422 Unprocessable Entity，并且响应正文将包含有关原因的详细信息验证失败。
（附带说明：pydantic 带有 constrained types，它允许约束基本数据类型而无需编写显式验证器。）
如果以上内容不令人满意并且您想更改行为，我将采用以下方法（有关 ValidationError 处理的详细信息，请参阅 here）：
from fastapi import Depends, FastAPI, Request, status
from fastapi.exceptions import RequestValidationError
from fastapi.exception_handlers import request_validation_exception_handler
from fastapi.responses import JSONResponse
from pydantic import BaseModel, conint
class RankInput(BaseModel):
# Constrained integer, must be greater that or equal to 0
# and less than or equal to 1 million.
rank: conint(ge=0, le=1_000_000)
async def rank_out_of_bound_handler(request: Request, exc: RequestValidationError):
validation_errors = exc.errors()
for err in validation_errors:
# You could check for other things here as well, e.g. the error type.
if "rank" in err["loc"]:
return JSONResponse(
status_code=status.HTTP_400_BAD_REQUEST,
content={"message": "Rank must be in range [0, 1000000]."}
)
# Default response in every other case.
return await request_validation_exception_handler(request, exc)
def get_info_by_rank(rank):
return rank
app = FastAPI(
exception_handlers={RequestValidationError: rank_out_of_bound_handler},
)
@app.get('/rank/{rank}')
async def get_rank(value: RankInput = Depends()):
result = get_info_by_rank(value.rank)
return result
对端点的调用现在给出：
$ curl -i "http://127.0.0.1:8000/rank/1"
HTTP/1.1 200 OK
date: Sat, 28 Aug 2021 20:47:58 GMT
server: uvicorn
content-length: 1
content-type: application/json
1
$ curl -i "http://127.0.0.1:8000/rank/-1"
HTTP/1.1 400 Bad Request
date: Sat, 28 Aug 2021 20:48:24 GMT
server: uvicorn
content-length: 49
content-type: application/json
{"message":"Rank must be in range [0, 1000000]."}
$ curl -i "http://127.0.0.1:8000/rank/1000001"
HTTP/1.1 400 Bad Request
date: Sat, 28 Aug 2021 20:48:51 GMT
server: uvicorn
content-length: 49
content-type: application/json
{"message":"Rank must be in range [0, 1000000]."}
如果您要添加使用相同模型的不同端点，异常处理程序也会自动处理，例如：
@app.get('/other-rank/{rank}')
async def get_other_rank(value: RankInput = Depends()):
result = get_info_by_rank(value.rank)
return result
$ curl -i "http://127.0.0.1:8000/other-rank/-1"
HTTP/1.1 400 Bad Request
date: Sat, 28 Aug 2021 20:54:16 GMT
server: uvicorn
content-length: 49
content-type: application/json
{"message":"Rank must be in range [0, 1000000]."}
如果这不是您要找的，您能否解释一下您为什么要提出 ValueError？
我在 Pydantic 中使用 FastAPI。
我的问题 - 我需要使用 Pydantic
引发 ValueErrorfrom fastapi import FastAPI
from pydantic import BaseModel, validator
from fastapi import Depends, HTTPException
app = FastAPI()
class RankInput(BaseModel):
rank: int
@validator('rank')
def check_if_value_in_range(cls, v):
"""
check if input rank is within range
"""
if not 0 < v < 1000001:
raise ValueError("Rank Value Must be within range (0,1000000)")
#raise HTTPException(status_code=400, detail="Rank Value Error") - this works But I am looking for a solution using ValueError
return v
def get_info_by_rank(rank):
return rank
@app.get('/rank/{rank}')
async def get_rank(value: RankInput = Depends()):
result = get_info_by_rank(value.rank)
return result
这段代码在引发 ValueError 时给出 Internal Server Error
INFO: 127.0.0.1:59427 - "GET /info/?rank=-1 HTTP/1.1" 500 Internal Server Error
ERROR: Exception in ASGI application
Traceback (most recent call last):
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/uvicorn/protocols/http/h11_impl.py", line 396, in run_asgi
result = await app(self.scope, self.receive, self.send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/uvicorn/middleware/proxy_headers.py", line 45, in __call__
return await self.app(scope, receive, send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/fastapi/applications.py", line 199, in __call__
await super().__call__(scope, receive, send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/applications.py", line 111, in __call__
await self.middleware_stack(scope, receive, send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/middleware/errors.py", line 181, in __call__
raise exc from None
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/middleware/errors.py", line 159, in __call__
await self.app(scope, receive, _send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/exceptions.py", line 82, in __call__
raise exc from None
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/exceptions.py", line 71, in __call__
await self.app(scope, receive, sender)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/routing.py", line 566, in __call__
await route.handle(scope, receive, send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/routing.py", line 227, in handle
await self.app(scope, receive, send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/routing.py", line 41, in app
response = await func(request)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/fastapi/routing.py", line 195, in app
dependency_overrides_provider=dependency_overrides_provider,
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/fastapi/dependencies/utils.py", line 550, in solve_dependencies
solved = await run_in_threadpool(call, **sub_values)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/concurrency.py", line 34, in run_in_threadpool
return await loop.run_in_executor(None, func, *args)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/concurrent/futures/thread.py", line 57, in run
result = self.fn(*self.args, **self.kwargs)
File "pydantic/main.py", line 400, in pydantic.main.BaseModel.__init__
pydantic.error_wrappers.ValidationError: 1 validation error for GetInput
rank
ValueError() takes no keyword arguments (type=type_error)
ERROR:uvicorn.error:Exception in ASGI application
Traceback (most recent call last):
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/uvicorn/protocols/http/h11_impl.py", line 396, in run_asgi
result = await app(self.scope, self.receive, self.send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/uvicorn/middleware/proxy_headers.py", line 45, in __call__
return await self.app(scope, receive, send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/fastapi/applications.py", line 199, in __call__
await super().__call__(scope, receive, send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/applications.py", line 111, in __call__
await self.middleware_stack(scope, receive, send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/middleware/errors.py", line 181, in __call__
raise exc from None
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/middleware/errors.py", line 159, in __call__
await self.app(scope, receive, _send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/exceptions.py", line 82, in __call__
raise exc from None
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/exceptions.py", line 71, in __call__
await self.app(scope, receive, sender)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/routing.py", line 566, in __call__
await route.handle(scope, receive, send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/routing.py", line 227, in handle
await self.app(scope, receive, send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/routing.py", line 41, in app
response = await func(request)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/fastapi/routing.py", line 195, in app
dependency_overrides_provider=dependency_overrides_provider,
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/fastapi/dependencies/utils.py", line 550, in solve_dependencies
solved = await run_in_threadpool(call, **sub_values)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/concurrency.py", line 34, in run_in_threadpool
return await loop.run_in_executor(None, func, *args)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/concurrent/futures/thread.py", line 57, in run
result = self.fn(*self.args, **self.kwargs)
File "pydantic/main.py", line 400, in pydantic.main.BaseModel.__init__
pydantic.error_wrappers.ValidationError: 1 validation error for GetInput
rank
ValueError() takes no keyword arguments (type=type_error)
我也检查了https://github.com/tiangolo/fastapi/issues/2180。
但是我想不出解决办法。
我需要做的是使用自定义状态代码提升 ValueError。
注意 - 我知道我可以通过提高 HTTPException 来完成工作。
但我正在寻找使用 ValueError
你能告诉我哪里错了吗？
还在 Github 上发布了此问题 - https://github.com/tiangolo/fastapi/issues/3761
如果您没有引发 HTTPException，那么通常任何其他未捕获的异常都会生成 500 响应（Internal Server Error）。如果您的意图是在引发特定异常时使用其他一些自定义错误消息和 HTTP 状态进行响应 - 例如 ValueError - 那么您可以使用向您的应用程序添加一个全局异常处理程序：
from fastapi import FastAPI, Request
from fastapi.responses import JSONResponse
@app.exception_handler(ValueError)
async def value_error_exception_handler(request: Request, exc: ValueError):
return JSONResponse(
status_code=400,
content={"message": str(exc)},
)
这将给出 400 响应（或者您可以将状态代码更改为您喜欢的任何内容），如下所示：
{
"message": "Value Must be within range (0,1000000)"
}
请注意，pydantic 期望验证者提出 ValueError、TypeError 或 AssertionError（参见 docs）pydantic将转换为 ValidationError.
此外，根据 FastAPI's documentation：
When a request contains invalid data, FastAPI internally raises a
RequestValidationError.
RequestValidationErroris a sub-class of Pydantic'sValidationError.
这样做的结果是 pydantic 模型验证期间出现的标准 Validation 错误将被转换为 422 Unprocessable Entity，并且响应正文将包含有关原因的详细信息验证失败。
（附带说明：pydantic 带有 constrained types，它允许约束基本数据类型而无需编写显式验证器。）
如果以上内容不令人满意并且您想更改行为，我将采用以下方法（有关 ValidationError 处理的详细信息，请参阅 here）：
from fastapi import Depends, FastAPI, Request, status
from fastapi.exceptions import RequestValidationError
from fastapi.exception_handlers import request_validation_exception_handler
from fastapi.responses import JSONResponse
from pydantic import BaseModel, conint
class RankInput(BaseModel):
# Constrained integer, must be greater that or equal to 0
# and less than or equal to 1 million.
rank: conint(ge=0, le=1_000_000)
async def rank_out_of_bound_handler(request: Request, exc: RequestValidationError):
validation_errors = exc.errors()
for err in validation_errors:
# You could check for other things here as well, e.g. the error type.
if "rank" in err["loc"]:
return JSONResponse(
status_code=status.HTTP_400_BAD_REQUEST,
content={"message": "Rank must be in range [0, 1000000]."}
)
# Default response in every other case.
return await request_validation_exception_handler(request, exc)
def get_info_by_rank(rank):
return rank
app = FastAPI(
exception_handlers={RequestValidationError: rank_out_of_bound_handler},
)
@app.get('/rank/{rank}')
async def get_rank(value: RankInput = Depends()):
result = get_info_by_rank(value.rank)
return result
对端点的调用现在给出：
$ curl -i "http://127.0.0.1:8000/rank/1"
HTTP/1.1 200 OK
date: Sat, 28 Aug 2021 20:47:58 GMT
server: uvicorn
content-length: 1
content-type: application/json
1
$ curl -i "http://127.0.0.1:8000/rank/-1"
HTTP/1.1 400 Bad Request
date: Sat, 28 Aug 2021 20:48:24 GMT
server: uvicorn
content-length: 49
content-type: application/json
{"message":"Rank must be in range [0, 1000000]."}
$ curl -i "http://127.0.0.1:8000/rank/1000001"
HTTP/1.1 400 Bad Request
date: Sat, 28 Aug 2021 20:48:51 GMT
server: uvicorn
content-length: 49
content-type: application/json
{"message":"Rank must be in range [0, 1000000]."}
如果您要添加使用相同模型的不同端点，异常处理程序也会自动处理，例如：
@app.get('/other-rank/{rank}')
async def get_other_rank(value: RankInput = Depends()):
result = get_info_by_rank(value.rank)
return result
$ curl -i "http://127.0.0.1:8000/other-rank/-1"
HTTP/1.1 400 Bad Request
date: Sat, 28 Aug 2021 20:54:16 GMT
server: uvicorn
content-length: 49
content-type: application/json
{"message":"Rank must be in range [0, 1000000]."}
如果这不是您要找的，您能否解释一下您为什么要提出 ValueError？