How to install

$ pip install aiohttp_pydantic

Example:

from typing import Optional

from aiohttp import web
from aiohttp_pydantic import PydanticView
from pydantic import BaseModel

# Use pydantic BaseModel to validate request body
class ArticleModel(BaseModel):
    name: str
    nb_page: Optional[int]


# Create your PydanticView and add annotations.
class ArticleView(PydanticView):

    async def post(self, article: ArticleModel):
        return web.json_response({'name': article.name,
                                  'number_of_page': article.nb_page})

    async def get(self, with_comments: Optional[bool]):
        return web.json_response({'with_comments': with_comments})


app = web.Application()
app.router.add_view('/article', ArticleView)
web.run_app(app)

$ curl -X GET http://127.0.0.1:8080/article?with_comments=a
[
  {
    "loc": [
      "with_comments"
    ],
    "msg": "value could not be parsed to a boolean",
    "type": "type_error.bool"
  }
]

$ curl -X GET http://127.0.0.1:8080/article?with_comments=yes
{"with_comments": true}

$ curl -H "Content-Type: application/json" -X post http://127.0.0.1:8080/article --data '{}'
[
  {
    "loc": [
      "name"
    ],
    "msg": "field required",
    "type": "value_error.missing"
  }
]

$ curl -H "Content-Type: application/json" -X post http://127.0.0.1:8080/article --data '{"name": "toto", "nb_page": "3"}'
{"name": "toto", "number_of_page": 3}

API:

class AccountView(PydanticView):
    async def get(self, customer_id: str, account_id: str, /):
        ...

app = web.Application()
app.router.add_get('/customers/{customer_id}/accounts/{account_id}', AccountView)

class AccountView(PydanticView):
    async def get(self, customer_id: str):
        ...

app = web.Application()
app.router.add_get('/customers', AccountView)

class Customer(BaseModel):
    first_name: str
    last_name: str

class CustomerView(PydanticView):
    async def post(self, customer: Customer):
        ...

app = web.Application()
app.router.add_view('/customers', CustomerView)

class CustomerView(PydanticView):
    async def get(self, *, authorization: str, expire_at: datetime):
        ...

app = web.Application()
app.router.add_view('/customers', CustomerView)

Add route to generate Open Api Specification

aiohttp_pydantic provides a sub-application to serve a route to generate Open Api Specification reading annotation in your PydanticView. Use aiohttp_pydantic.oas.setup() to add the sub-application

from aiohttp import web
from aiohttp_pydantic import oas


app = web.Application()
oas.setup(app)

By default, the route to display the Open Api Specification is /oas but you can change it using url_prefix parameter

oas.setup(app, url_prefix='/spec-api')

If you want generate the Open Api Specification from several aiohttp sub-application. on the same route, you must use apps_to_expose parameters

from aiohttp import web
from aiohttp_pydantic import oas

app = web.Application()
sub_app_1 = web.Application()

oas.setup(app, apps_to_expose=[app, sub_app_1])