Pydantic的可选参数尚未准备好，因此类型仍然是一个ForwardRef。
Pydantic的可选参数尚未准备好，因此类型仍然是一个ForwardRef。
我有以下代码：
endpoints.py
from __future__ import annotations # 这一行非常重要，需要放在顶部
from fastapi import FastAPI
from pydantic import BaseModel
from typing import List, Optional
class MyOpt(BaseModel):
fieldfirst: str = "S"
fieldsecond: int = 1
fieldthird: Optional[str] = None
fieldforth: List[int] = []
fieldfifth: int
fieldsixth: List[Optional[int]] = [None, None]
fieldseventh: Optional[str] = None
fieldeighth: Optional[int] = None
fieldnineth: Optional[str] = None
fieldtenth: Optional[List[Optional[int]]] = [None, None]
# 创建 FastAPI 对象
app = FastAPI()
# API 端点开始
@app.get("/", tags=["root"])
def root():
return {"message": "REST API."}
# -- 测试端点 --
@app.get(
"/health",
name="health",
tags=["root"],
summary="Test connection to API",
status_code=200
)
def health():
return {"type": "complete"}
@app.post(
"/send_instruction",
name="send_instruction",
tags=["web"],
)
def send_instruction(myopts: MyOpt = None):
return {"result": "ok"}
run_api.py:
import uvicorn
if __name__ == "__main__":
uvicorn.run("endpoints:app", host="0.0.0.0", port=8822, reload=True, access_log=False)
当我调用 API（python3 run_api.py）时，只有在发送 MyOpt 的可选值时才会出现以下错误：
File "/home/ubuntu/.local/lib/python3.10/site-packages/uvicorn/protocols/http/h11_impl.py", line 403, in run_asgi
result = await app(self.scope, self.receive, self.send)
File "/home/ubuntu/.local/lib/python3.10/site-packages/uvicorn/middleware/proxy_headers.py", line 78, in __call__
return await self.app(scope, receive, send)
File "/home/ubuntu/.local/lib/python3.10/site-packages/fastapi/applications.py", line 269, in __call__
await super().__call__(scope, receive, send)
File "/home/ubuntu/.local/lib/python3.10/site-packages/starlette/applications.py", line 124, in __call__
await self.middleware_stack(scope, receive, send)
File "/home/ubuntu/.local/lib/python3.10/site-packages/starlette/middleware/errors.py", line 184, in __call__
raise exc
File "/home/ubuntu/.local/lib/python3.10/site-packages/starlette/middleware/errors.py", line 162, in __call__
await self.app(scope, receive, _send)
File "/home/ubuntu/.local/lib/python3.10/site-packages/starlette/exceptions.py", line 93, in __call__
raise exc
File "/home/ubuntu/.local/lib/python3.10/site-packages/starlette/exceptions.py", line 82, in __call__
await self.app(scope, receive, sender)
File "/home/ubuntu/.local/lib/python3.10/site-packages/fastapi/middleware/asyncexitstack.py", line 21, in __call__
raise e
File "/home/ubuntu/.local/lib/python3.10/site-packages/fastapi/middleware/asyncexitstack.py", line 18, in __call__
await self.app(scope, receive, send)
File "/home/ubuntu/.local/lib/python3.10/site-packages/starlette/routing.py", line 670, in __call__
await route.handle(scope, receive, send)
File "/home/ubuntu/.local/lib/python3.10/site-packages/starlette/routing.py", line 266, in handle
await self.app(scope, receive, send)
File "/home/ubuntu/.local/lib/python3.10/site-packages/starlette/routing.py", line 65, in app
response = await func(request)
File "/home/ubuntu/.local/lib/python3.10/site-packages/fastapi/routing.py", line 217, in app
solved_result = await solve_dependencies(
File "/home/ubuntu/.local/lib/python3.10/site-packages/fastapi/dependencies/utils.py", line 557, in solve_dependencies
) = await request_body_to_args( # body_params checked above
File "/home/ubuntu/.local/lib/python3.10/site-packages/fastapi/dependencies/utils.py", line 692, in request_body_to_args
v_, errors_ = field.validate(value, values, loc=loc)
File "pydantic/fields.py", line 857, in pydantic.fields.ModelField.validate
File "pydantic/fields.py", line 1074, in pydantic.fields.ModelField._validate_singleton
File "pydantic/fields.py", line 1121, in pydantic.fields.ModelField._apply_validators
File "pydantic/class_validators.py", line 313, in pydantic.class_validators._generic_validator_basic.lambda12
File "pydantic/main.py", line 686, in pydantic.main.BaseModel.validate
File "pydantic/main.py", line 339, in pydantic.main.BaseModel.__init__
File "pydantic/main.py", line 1038, in pydantic.main.validate_model
File "pydantic/fields.py", line 833, in pydantic.fields.ModelField.validate
pydantic.errors.ConfigError: field "fieldnineth" not yet prepared so type is still a ForwardRef, you might need to call SatOpt.update_forward_refs().
我使用 Postman 发送请求，在 Body 中选择 raw 格式，格式化为 JSON，内容如下：
{
"fieldfirst": "S",
"fieldsecond": 1,
"fieldthird": "a test",
"fieldforth": [1, 2],
"fieldfifth": 42,
"fieldsixth": [
[1, 8, 3],
[1, 9, 2]
],
"fieldseventh": "yey",
"fieldnineth": "VV"
}
我的代码有什么问题？