How can I access s3 files in Python using urls?

Question

I want to write a Python script that will read and write files from s3 using their url\'s, eg:\'s3:/mybucket/file\'. It would need to run locally and in the cloud without a

Answer 1

Here's how they do it in awscli :

def find_bucket_key(s3_path):
    """
    This is a helper function that given an s3 path such that the path is of
    the form: bucket/key
    It will return the bucket and the key represented by the s3 path
    """
    s3_components = s3_path.split('/')
    bucket = s3_components[0]
    s3_key = ""
    if len(s3_components) > 1:
        s3_key = '/'.join(s3_components[1:])
    return bucket, s3_key


def split_s3_bucket_key(s3_path):
    """Split s3 path into bucket and key prefix.
    This will also handle the s3:// prefix.
    :return: Tuple of ('bucketname', 'keyname')
    """
    if s3_path.startswith('s3://'):
        s3_path = s3_path[5:]
    return find_bucket_key(s3_path)

Which you could just use with code like this

from awscli.customizations.s3.utils import split_s3_bucket_key
import boto3
client = boto3.client('s3')
bucket_name, key_name = split_s3_bucket_key(
    's3://example-bucket-name/path/to/example.txt')
response = client.get_object(Bucket=bucket_name, Key=key_name)

This doesn't address the goal of interacting with an s3 key as a file like object but it's a step in that direction.