Python boto，列出桶中特定目录的内容

Question

我只能通过 S3 访问 S3 存储桶中的特定目录。

例如，如果我尝试列出整个存储桶，则使用 s3cmd 命令：

    $ s3cmd ls s3://bucket-name

我收到一个错误：Access to bucket 'my-bucket-url' was denied

但是如果我尝试访问存储桶中的特定目录，我可以看到内容：

    $ s3cmd ls s3://bucket-name/dir-in-bucket

现在我想用 python boto 连接到 S3 存储桶。类似：

    bucket = conn.get_bucket('bucket-name')

我收到一个错误：boto.exception.S3ResponseError: S3ResponseError: 403 Forbidden

但如果我尝试：

    bucket = conn.get_bucket('bucket-name/dir-in-bucket')

脚本暂停大约 10 秒，然后打印出错误。波纹管是完整的跟踪。知道如何进行吗？

注意问题是关于 boto 版本 2 模块，而不是 boto3。

Traceback (most recent call last):
  File "test_s3.py", line 7, in <module>
    bucket = conn.get_bucket('bucket-name/dir-name')
  File "/usr/local/lib/python2.7/dist-packages/boto/s3/connection.py", line 471, in get_bucket
    return self.head_bucket(bucket_name, headers=headers)
  File "/usr/local/lib/python2.7/dist-packages/boto/s3/connection.py", line 490, in head_bucket
    response = self.make_request('HEAD', bucket_name, headers=headers)
  File "/usr/local/lib/python2.7/dist-packages/boto/s3/connection.py", line 633, in make_request
    retry_handler=retry_handler
  File "/usr/local/lib/python2.7/dist-packages/boto/connection.py", line 1046, in make_request
    retry_handler=retry_handler)
  File "/usr/local/lib/python2.7/dist-packages/boto/connection.py", line 922, in _mexe
    request.body, request.headers)
  File "/usr/lib/python2.7/httplib.py", line 958, in request
    self._send_request(method, url, body, headers)
  File "/usr/lib/python2.7/httplib.py", line 992, in _send_request
    self.endheaders(body)
  File "/usr/lib/python2.7/httplib.py", line 954, in endheaders
    self._send_output(message_body)
  File "/usr/lib/python2.7/httplib.py", line 814, in _send_output
    self.send(msg)
  File "/usr/lib/python2.7/httplib.py", line 776, in send
    self.connect()
  File "/usr/lib/python2.7/httplib.py", line 1157, in connect
    self.timeout, self.source_address)
  File "/usr/lib/python2.7/socket.py", line 553, in create_connection
    for res in getaddrinfo(host, port, 0, SOCK_STREAM):
socket.gaierror: [Errno -2] Name or service not known

Answer 1

对于boto3

import boto3

s3 = boto3.resource('s3')
my_bucket = s3.Bucket('my_bucket_name')

for object_summary in my_bucket.objects.filter(Prefix="dir_name/"):
    print(object_summary.key)

Answer 2

默认情况下，当您在 boto 中调用 get_bucket 时，它会尝试通过对存储桶 URL 执行 HEAD 请求来验证您是否确实有权访问该存储桶。在这种情况下，您不希望 boto 这样做，因为您无权访问存储桶本身。所以，这样做：

bucket = conn.get_bucket('my-bucket-url', validate=False)

然后你应该能够做这样的事情来列出对象：

for key in bucket.list(prefix='dir-in-bucket'): 
    <do something>

如果仍然出现 403 错误，请尝试在前缀末尾添加斜杠。

for key in bucket.list(prefix='dir-in-bucket/'): 
    <do something>

注意：这个答案是关于 boto version 2 模块的，现在已经过时了。目前（2020 年），boto3 是使用 AWS 的标准模块。有关更多信息，请参阅此问题：What is the difference between the AWS boto and boto3

Answer 3

Boto3 客户端：

import boto3

_BUCKET_NAME = 'mybucket'
_PREFIX = 'subfolder/'

client = boto3.client('s3', aws_access_key_id=ACCESS_KEY,
                            aws_secret_access_key=SECRET_KEY)

def ListFiles(client):
    """List files in specific S3 URL"""
    response = client.list_objects(Bucket=_BUCKET_NAME, Prefix=_PREFIX)
    for content in response.get('Contents', []):
        yield content.get('Key')

file_list = ListFiles(client)
for file in file_list:
    print 'File found: %s' % file

使用会话

from boto3.session import Session

_BUCKET_NAME = 'mybucket'
_PREFIX = 'subfolder/'

session = Session(aws_access_key_id=ACCESS_KEY,
                  aws_secret_access_key=SECRET_KEY)

client = session.client('s3')

def ListFilesV1(client, bucket, prefix=''):
    """List files in specific S3 URL"""
    paginator = client.get_paginator('list_objects')
    for result in paginator.paginate(Bucket=bucket, Prefix=prefix,
                                     Delimiter='/'):
        for content in result.get('Contents', []):
            yield content.get('Key')

file_list = ListFilesV1(client, _BUCKET_NAME, prefix=_PREFIX)
for file in file_list:
    print 'File found: %s' % file

Answer 4

我也遇到了同样的问题，这段代码可以解决问题。

import boto3

s3 = boto3.resource("s3")
s3_bucket = s3.Bucket("bucket-name")
dir = "dir-in-bucket"
files_in_s3 = [f.key.split(dir + "/")[1] for f in 
s3_bucket.objects.filter(Prefix=dir).all()]

Answer 5

以下代码将列出 S3 存储桶特定目录中的所有文件：

import boto3

s3 = boto3.client('s3')

def get_all_s3_keys(s3_path):
    """
    Get a list of all keys in an S3 bucket.

    :param s3_path: Path of S3 dir.
    """
    keys = []

    if not s3_path.startswith('s3://'):
        s3_path = 's3://' + s3_path

    bucket = s3_path.split('//')[1].split('/')[0]
    prefix = '/'.join(s3_path.split('//')[1].split('/')[1:])

    kwargs = {'Bucket': bucket, 'Prefix': prefix}
    while True:
        resp = s3.list_objects_v2(**kwargs)
        for obj in resp['Contents']:
            keys.append(obj['Key'])

        try:
            kwargs['ContinuationToken'] = resp['NextContinuationToken']
        except KeyError:
            break

    return keys

Answer 6

这可以使用：

s3_client = boto3.client('s3')
objects = s3_client.list_objects_v2(Bucket='bucket_name')
for obj in objects['Contents']:
  print(obj['Key'])

Answer 7

如果要列出存储桶中某个文件夹的所有对象，可以在列出时指定。

import boto
conn = boto.connect_s3(AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY)
bucket = conn.get_bucket(AWS_BUCKET_NAME)
for file in bucket.list("FOLDER_NAME/", "/"):
    <do something with required file>