mayim 0.3.0

The NOT ORM hydraroe

Mayim

The NOT ORM Python hydrator

What is Mayim?

The simplest way to describe it would be to call it a one-way ORM. That is to say that it does not craft SQL statements for you. Think of it as BYOQ (Bring Your Own Query).

Why?

I have nothing against ORMs, truthfully. They serve a great purpose and can be the right tool for the job in many situations. I just prefer not to use them where possible. Instead, I would rather have control of my SQL statements.

The typical tradeoff though is that there is more work needed to hydrate from SQL queries to objects. Mayim aims to solve that.

Getting Started

pip install mayim[postgres]

import asyncio
from typing import List
from mayim import Mayim, PostgresExecutor, sql
from dataclasses import dataclass

@dataclass
class Person:
    name: str

class PersonExecutor(PostgresExecutor):
    @sql("SELECT * FROM people LIMIT $limit OFFSET $offset")
    async def select_all_people(
        self, limit: int = 4, offset: int = 0
    ) -> List[Person]:
        ...

async def run():
    executor = PersonExecutor()
    Mayim(dsn="postgres://...")
    print(await executor.select_all_cities())


asyncio.run(run())

Documentation

The docs: ahopkins.github.io/mayim

Framework support

Quart

Mayim can attach to Quart using the customary init_app pattern and will handle setting up Mayim and the lifecycle events.

from quart import Quart
from dataclasses import asdict
from typing import List
from mayim import PostgresExecutor
from model import City
from mayim.extension import QuartMayimExtension

app = Quart(__name__)


class CityExecutor(PostgresExecutor):
    async def select_all_cities(
        self, limit: int = 4, offset: int = 0
    ) -> List[City]:
        ...


ext = QuartMayimExtension(
    executors=[CityExecutor],
    dsn="postgres://postgres:postgres@localhost:5432/world",
)
ext.init_app(app)


@app.route("/")
async def handler():
    executor = CityExecutor()
    cities = await executor.select_all_cities()
    return {"cities": [asdict(city) for city in cities]}

Sanic

Mayim uses Sanic Extensions v22.6+ to extend your Sanic app. It starts Mayim and provides dependency injections into your routes of all of the executors

from typing import List
from dataclasses import asdict
from sanic import Sanic, Request, json
from sanic_ext import Extend
from mayim import Mayim
from mayim.executor import Executor
from mayim.extensions import MayimExtension


class CityExecutor(Executor):
    async def select_all_cities(
        self, limit: int = 4, offset: int = 0
    ) -> List[City]:
        ...


app = Sanic(__name__)
Extend.register(
    MayimExtension(
        executors=[CityExecutor], dsn="postgres://..."
    )
)


@app.get("/")
async def handler(request: Request, executor: CityExecutor):
    cities = await executor.select_all_cities()
    return json({"cities": [asdict(city) for city in cities]})