aiohttp_validate

Simple library that helps you validate your API endpoints requests/responses with jsonschema. Requires Python 3.9+ and aiohttp 3.8+.

Installation

Install from PyPI:

pip install aiohttp_validate

Usage

Complete example of validation for text tokenization microservice:

from aiohttp_validate import validate

@validate(
    request_schema={
        "type": "object",
        "properties": {
            "text": {"type": "string"},
        },
        "required": ["text"],
        "additionalProperties": False
    },
    response_schema={
        "type": "array",
        "items": {
            "type": "array",
            "items": {
                "type": "array",
                "items": {"type": "string"}
            }
        }
    }
)
async def tokenize_text_handler(request, *args):
    return tokenize_text(request["text"])

The wrapped handler receives the parsed and validated JSON body as its first argument and the original aiohttp request object as the second:

async def handler(data, request):
    pool = request.app["redis_pool"]  # the real request is right here
    ...

To respond with a status code other than 200, return a (data, status) tuple:

async def create_handler(data, request):
    return {"id": new_id}, 201

The tuple form is detected by shape (a 2-tuple ending in an int), so if your response data is itself such a tuple, return it as a list instead — JSON has no tuples, the wire format is identical — or return a ready web.json_response.

To also validate string formats (date, email, ...), pass a format checker (extra format support follows jsonschema's rules):

@validate(request_schema=..., format_checker=jsonschema.FormatChecker())

Features

• The decorator to (optionally) validate the request to your aiohttp endpoint and it's response.
• Easily integrates with aiohttp_swaggerify to automatically document your endpoints with swagger.
• Validation errors are standardized and can be easily parsed by the clients of your service and also human-readable.

Developing

Install with test dependencies and launch tests:

pip install -e .[test]
pytest

Credits

That package is influenced by Tornado-JSON written by Hamza Faran Code to parse errors is written by Ruslan Karalkin

Versioning

This software follows Semantic Versioning

License

• Free software: MIT license