How to get more than 1000 objects from S3 by using list_objects_v2?

Question

I have more than 500,000 objects on s3. I am trying get the size of each object. I am using the following python code for that

Answer 1

Use the ContinuationToken returned in the response as a parameter for subsequent calls, until the IsTruncated value returned in the response is false.

This can be factored into a neat generator function:

def get_all_s3_objects(s3, **base_kwargs):
    continuation_token = None
    while True:
        list_kwargs = dict(MaxKeys=1000, **base_kwargs)
        if continuation_token:
            list_kwargs['ContinuationToken'] = continuation_token
        response = s3.list_objects_v2(**list_kwargs)
        yield from response.get('Contents', [])
        if not response.get('IsTruncated'):  # At the end of the list?
            break
        continuation_token = response.get('NextContinuationToken')

for file in get_all_s3_objects(boto3.client('s3'), Bucket=bucket, Prefix=prefix):
    print(file['size'])