aioproperty 0.2.9

truely async properties

Install

pip3 install aioproperty

Documentation

You can find documentation here

Description

aioproperty presents async properties with both async getter and setter in one place.

Example:

from aioproperty import aioproperty
import asyncio

class SomeClass:
    
    @aioproperty
    async def hello(self, value):
        await asyncio.sleep(1)
        return value

some_obj = SomeClass()
some_obj.hello = 'hello'

async def run():
    print(await some_obj.hello)

asyncio.run(run())

aioproperty is not a property in a classic meaning, it keeps values inside asincio tasks. Once you set a new value, it is scheduled in a task. If any task is running now, it will wait untill it is finished. When you get value, you actually get a current task, and you can await it to get a value. More of that: you can use math without awaiting like that:

other = some_obj.hello + ' byby'
print(await other)

We also introduce chaining:

class SomeClass:
    
    @aioproperty
    async def hello(self, value):
        await asyncio.sleep(1)
        return value
    
    @hello.chain
    async def some_more(self, value):
        push_value(value)

Chains works like a reducer. It applies each function to a new value iteratively. It can return value or return nothing. If nothing is return, the value will be kept asis. Any chained function is inserted by default in the end of chain, but you can control it with a priority parameter, or with is_first parameter. If is_first is True, it will be inserted in the beginning of the chain.

You can also use inheritance and modify inhereted properties with our special decorator inject:

class Parent:
    
    @aioproperty
    async def hello(self, value):
        await asyncio.sleep(1)
        return value
    
    @hello.chain
    async def some_more(self, value):
        push_value(value)

class Child(Parent):
    
    @inject(Parent.hello, priority=100)
    async def injected_method(self, value):
        print('hello from injection')
    
    #another form of injection using name of a property
    @inject('hello')
    async def injected_method_2(self, value):
        print('hello from injection 2')

Read more in our docs