The asyncio client for Amazon S3
Switch branches/tags
Nothing to show
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.


Asyncio S3 Bindings

Status: Alpha

The aio-s3 is a small library for accessing Amazon S3 Service that leverages python's standard asyncio library.

Only read operations are supported so far, contributions are welcome.


Basically all methods supported so far are shown in this example:

import asyncio
from aios3.bucket import Bucket

def main():
    bucket = Bucket('some-bucket-name',

    # List keys based on prefix
    lst = yield from bu.list('some-prefix')

    # Get contents file as a string
    response = yield from bu.get(lst[0])

    # Get file contents by chunks
    response = yield from[0])
    while 1:
        chunk = yield from
        print("Got chunk of ", len(chunk), "bytes")
        if not chunk:



Bucket(name, *, aws_key, aws_secret, aws_region, aws_endpoint, connector):
Creates a wrapper object for accessing S3 bucket. Note unlike in many other bindings you need to specify aws_region (and probably aws_endpoint) correctly (see a table). The connector is an aiohttp connector, which might be used to setup proxy or other useful things.
Bucket.list(prefix='', max_keys=1000):

Lists items which start with prefix. Each returned item is a Key object. This method is coroutine.


This method raises assertion error if there are more keys than max_keys. We do not have a method to return keys iteratively yet.

Fetches object names key. The key might be a string or Key object. Returns bytes. This method is coroutine.
Allows iteratively download the key. The object returned by the coroutine is an object having method .read(bufsize) which is a coroutine too.

Represents an S3 key returned by Bucket.list. Key has at least the following attributes:

  • key -- the full name of the key stored in a bucket
  • last_modified -- datetime.datetime object
  • etag -- The ETag, usually md5 of the content with additional quotes
  • size -- Size of the object in bytes
  • storage_class -- Storage class of the object