python - pydantic 模型动态字段数据类型

Question

我想根据特定条件动态分配字段数据类型。以下是我的模型:

class Connection(BaseModel):
    name: str
    # type can be GCS or ORACLE
    type: str
    details: GCSDetails/OracleDetails

class GCSDetails(BaseModel):
    bucket: str
    folderName: str

class OracleDetails(BaseModel):
    host: str
    port: int
    user: str

那么，基于“类型”，即 GCS 或 ORACLE，我如何在验证期间动态更改“详细信息”数据类型？

Answer 1

Pydantic 无需使用额外的 type 字段即可通过 Union 类型做到这一点，because

pydantic will attempt to 'match' any of the types defined under Union and will use the first one that matches.

from typing import Union

from pydantic import BaseModel


class GCSDetails(BaseModel):
    bucket: str
    folderName: str


class OracleDetails(BaseModel):
    host: str
    port: int
    user: str


class Connection(BaseModel):
    name: str
    # type can be GCS or ORACLE
    type: str
    details: Union[GCSDetails, OracleDetails]


test_gcs = {"name": "", "type": "GCS", "details": {"bucket": "", "folderName": ""}}
test_oracle = {"name": "", "type": "ORACLE", "details": {"host": "", "port": 15, "user": ""}}

print(Connection(**test_gcs))
print(Connection(**test_oracle))

输出:

name='' type='GCS' details=GCSDetails(bucket='', folderName='')
name='' type='ORACLE' details=OracleDetails(host='', port=15, user='')