aio-throttle-to-next-second

Throttler for asyncio Python that throttles to the next whole second, as reported by time.time(). This is useful to force an order on requests to a service that uses a "latest timestamp wins" strategy, such as S3.

Installation

pip install aio-throttle-to-next-second

Usage

Create a shared Throttler, with no arguments

from aio_throttle_to_next_second import Throttler

throttler = Throttler()

and then just before the piece(s) of code to be throttled, call this and await its result.

await throttler()
# Each execution reaching this line will reach this line at a different second

Example: multiple tasks throttled

import asyncio
import time

from aio_throttle_to_next_second import Throttler

async def main():
    throttler = Throttler()
    await asyncio.gather(*[
        worker(throttler) for _ in range(10)
    ])

async def worker(throttler):
    await throttler()
    # Each print will show a distinct second, though all workers started together
    print(int(time.time()))

loop = asyncio.get_event_loop()
loop.run_until_complete(main())
loop.close()

Example: single task throttled

import asyncio
import random
import time

from aio_throttle_to_next_second import Throttler

async def main():
    throttler = Throttler()
    for _ in range(10):
        await throttler()
        # Each print will show a distinct second, though there is a random sleep
        print(int(time.time()))
        await asyncio.sleep(random.random())

loop = asyncio.get_event_loop()
loop.run_until_complete(main())
loop.close()