Decode URL strings with Pydantic

I am using Pydantic to validate and type an incoming S3 Event in an AWS Lambda function.

The event looks like this (only including relevant bits):

{"Records": [    {"s3": {"bucket": {"name": "my-bucket"        },"object": {"key": "MYKEY%28CSV%29/XXXX.CSV"        }      }    }  ]}

I define my Model like this to get the relevant information.

from pydantic import BaseModelclass ObjectInfo(BaseModel):    key: strclass BucketInfo(BaseModel):    name: strclass S3Schema(BaseModel):    bucket: BucketInfo    object: ObjectInfoclass Record(BaseModel):    s3: S3Schemaclass DeletionEvent(BaseModel):    Records: list[Record]def handler(event: dict, _):    eventTyped = DeletionEvent(**event)    return True

Now the problem is that the correct value for key is supposed to be MYKEY(CSV)/XXXX.CSV, not MYKEY%28CSV%29/XXXX.CSV. I usually fix this issue using urllib.parse.unquote_plus to decode the %XX bits representing special characters. I think I can define a custom decoder but this seems like overkill.

Is there any way to get pydantic to do this decoding for me? It has a bunch of classes for working with URLs but I don't see anything about decoding URL encoded strings by themselves.