json-entity

simple-json-db

This is a simple json database. The package provides a simple ORM between python objects and json objects with a well type-hinted schema.

engine = AppEngine()

async with engine.students as students:
    students.add_range(Student("John", "Doe"), Student("Jane", "Doe"))

async for student in engine.students:
    print(student.first_name, student.last_name)
    # Can you guess ? )

This package maps your python objects to json and then you can save, get, modify or delete them using async methods.

This package is for tiny and simple projects. with a low amount of data.

Installation

The package is available at PYPI as json-entity.

Intro

Let's see how you can get started with the package.

See also our Wiki.

You can take a look at src/examples, if you're not on reading mode.

Quick Start

This data base consist of 3 main elements:

1- Model

It's obvious that you should have a model for your data to save, update, or ...

Since this library works with json, your model can contain everything
that JSON can.

2- Collection

You have a collection of data for every model, therefor,
The relation between Model and Collection is one to one.

3- Engine

This is where all collections are operate.

So, Every Engine has some Collections where each collection contains a set of an unique Model.

Let's create a model

Models are simple python class.

from sjd import TEntity, Engine, properties as props

@props.auto_collect()
class Person(TEntity):
    def __init__(self, first_name: int, last_name: str, age: int):
        self.first_name = first_name
        self.last_name = last_name
        self.age = age

Using auto_collect() method, the model will automatically collect properties form __init__ method.

Creating collection ?

It's really not necessary to create a collection by your own! And maybe you better )

Let us do that for ya ( Of course you can create customized Collections ).

Setup engine

Now you need to setup database's engine and define your collections there.

# ---- sniff ----

class AppEngine(Engine):
    __db_path__ = "my_database"
    persons = Engine.set(Person)

That's all you need to do for now.

Fire up

Now it's time for some fireworks 🎇.

Since the package is async, you'll need an event loop for it.

import asyncio

# ---- sniff ----

async def main():
    ...


if __name__ == "__main__":
    asyncio.run(main())

Now you can work with database inside main function.

async def main():

    engine = AppEngine()
    collection = engine.persons

    async with collection:
        collection.add_range(
            Person("John", "Doe", 20),
            Person("Jane", "Doe", 21),
            Person("Jack", "jones", 22),
            Person("Jill", "jones", 23),
        )

Iterate over all persons in the collection

async for person in collection:
    print(person.first_name, person.last_name, person.age)

You can do more advanced query stuff with queryable context.

async with collection.get_queryable() as persons:
    async for person in persons.where(lambda p: p.age > 21):
        print(person.first_name, person.last_name, person.age)

Or get only one directly.

target = await collection.get_first_async(lambda s: s.first_name, "John")

You can easily update your data:

async with collection.get_queryable() as persons:
    async for person in persons.where(lambda p: p.last_name == "jones"):
        person.last_name = "Jones"

await collection.save_changes_async()

Or even delete them ...

async with collection.get_queryable() as persons:
    async for person in persons.where(lambda p: p.last_name == "Doe"):
        collection.delete(person)

await collection.save_changes_async()

There're a lot more! see src/examples.