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

import boto3

bucket = 'bucket'
prefix = 'prefix'

contents = boto3.client('s3').list_objects_v2(Bucket=bucket,  MaxKeys=1000, Prefix=prefix)["Contents"]

for c in contents:
    print(c["Size"])

But it just gave me the size of top 1000 objects. Based on the documentation we can't get more 1000. Is there any way I can get more than that?

Answer 1

内置的 boto3Paginator类是克服 1000 条记录限制的最简单方法list-objects-v2。这可以实现如下

s3 = boto3.client('s3')

paginator = s3.get_paginator('list_objects_v2')
pages = paginator.paginate(Bucket='bucket', Prefix='prefix')

for page in pages:
    for obj in page['Contents']:
        print(obj['Size'])

更多详情：https : //boto3.amazonaws.com/v1/documentation/api/latest/reference/services/s3.html#S3.Paginator.ListObjectsV2

Answer 2

使用响应中返回的ContinuationToken作为后续调用的参数，直到响应中返回的IsTruncated值为false。

这可以分解成一个整洁的生成器函数：

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'])

Answer 3

如果您不需要使用 ，则boto3.client可以使用它boto3.resource来获取文件的完整列表：

s3r = boto3.resource('s3')
bucket = s3r.Bucket('bucket_name')
files_in_bucket = list(bucket.objects.all())

然后得到大小：

sizes = [f.size for f in files_in_bucket]

根据您的存储桶的大小，这可能需要一分钟。