FastAPI 请求中不可散列的类型

Question

我正在使用 fastapi 编写 post-api。所需的请求格式为：

{
   "leadid":LD123,
   "parties":[
      {
         "uid":123123,
         "cust_name":"JOhn Doe",
      }, ...]}

python中的快速api代码是：

class Customer(BaseModel):
    UID: str
    CustName: str

class PackageIn(BaseModel): 
    lead_id: str
    parties: Set[Customer]
    # threshold: Optional[int] = 85

app = FastAPI()

@app.post('/')
async def nm_v2(package:PackageIn):
    return {"resp":"Response"}

当我访问 SwaggerUI 提交响应时，错误是 “422 错误：无法处理的实体”。此外，SwaggerUI 文档指出

{
  "detail": [
    {
      "loc": [
        "body"
      ],
      "msg": "unhashable type: 'Customer'",
      "type": "type_error"
    }
  ]
}

我不知道如何在不创建一个单独的基于 pydantic 的 class 名为 Customer 的情况下为请求负载创建此 dict() 结构。请告诉我如何纠正错误。

Answer 1

Pytdantic BaseClass 不可哈希。关于此功能有一个discussion，我想它不会实现。讨论中有解决方法，对于你的情况，你可以试试这个：

from pydantic import BaseModel
from typing import Set


class MyBaseModel(BaseModel):
    def __hash__(self):  # make hashable BaseModel subclass
        return hash((type(self),) + tuple(self.__dict__.values()))


class Customer(MyBaseModel):  # Use hashable sublclass for your model
    UID: str
    CustName: str


class PackageIn(BaseModel):
    lead_id: str
    parties: Set[Customer]
    # threshold: Optional[int] = 85

data = {
    "lead_id": 'LD123',
    "parties": [
       {
           "UID": 123123,
           "CustName": "JOhn Doe",
       }]}

PackageIn.parse_obj(data) # This part fastapi will make on post request, just for test

> <PackageIn lead_id='LD123' parties={<Customer UID='123123' CustName='JOhn Doe'>}>

FastAPI 请求中不可散列的类型

Unhashable type in FastAPI request

python

fastapi

pydantic