当我的 JSON 是这样的时候，如何为我的 FastAPI 端点创建一个 Pydantic 模型？答案

【问题标题】：How can I create a Pydantic Model for my FastAPI endpoint when my JSON is something like this?当我的 JSON 是这样的时候，如何为我的 FastAPI 端点创建一个 Pydantic 模型？
【发布时间】：2021-05-02 15:32:26
【问题描述】：

{
  'events': [
    {
      'type': 'message',
      'replyToken': '0bc647fc5282423cde13fffbc947a8',
      'source': {
        'userId': 'U996ed69353d3c962ee17b33d9af3e2',
        'type': 'user'
      },
      'timestamp': 161185209914,
      'mode': 'active',
      'message': {
        'type': 'text',
        'id': '1346188304367',
        'text': ' hello'
      }
    }
  ],
  'destination': 'Uf44eb3ba6c4b87adbfaa4a517e'
}

这是我正在使用的 webhook 中的 json 它是这样包含的，我怎样才能为它写一个 Pytantic 模型？

【问题讨论】：

标签： fastapi pydantic

【解决方案1】：

这应该适用于您上面给出的请求正文。

from pydantic import BaseModel
from typing import List

class Source(BaseModel):
    userId: str
    type: str


class Message(BaseModel):
    type: str
    id: str
    text: str


class Event(BaseModel):
    type: str
    replyToken: str
    source: Source
    timestamp: int
    mode: str
    message: Message


class Webhook(BaseModel):
    events: List[Event]
    destination: str

这是 Webhook 模型的 OpenAPI 架构。

{
  "title": "Webhook",
  "type": "object",
  "properties": {
    "events": {
      "title": "Events",
      "type": "array",
      "items": {
        "$ref": "#/definitions/Event"
      }
    },
    "destination": {
      "title": "Destination",
      "type": "string"
    }
  },
  "required": [
    "events",
    "destination"
  ],
  "definitions": {
    "Source": {
      "title": "Source",
      "type": "object",
      "properties": {
        "userId": {
          "title": "Userid",
          "type": "string"
        },
        "type": {
          "title": "Type",
          "type": "string"
        }
      },
      "required": [
        "userId",
        "type"
      ]
    },
    "Message": {
      "title": "Message",
      "type": "object",
      "properties": {
        "type": {
          "title": "Type",
          "type": "string"
        },
        "id": {
          "title": "Id",
          "type": "string"
        },
        "text": {
          "title": "Text",
          "type": "string"
        }
      },
      "required": [
        "type",
        "id",
        "text"
      ]
    },
    "Event": {
      "title": "Event",
      "type": "object",
      "properties": {
        "type": {
          "title": "Type",
          "type": "string"
        },
        "replyToken": {
          "title": "Replytoken",
          "type": "string"
        },
        "source": {
          "$ref": "#/definitions/Source"
        },
        "timestamp": {
          "title": "Timestamp",
          "type": "integer"
        },
        "mode": {
          "title": "Mode",
          "type": "string"
        },
        "message": {
          "$ref": "#/definitions/Message"
        }
      },
      "required": [
        "type",
        "replyToken",
        "source",
        "timestamp",
        "mode",
        "message"
      ]
    }
  }
}

【讨论】：