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KS3 SDK for python使用指南

开发前准备

安装python sdk

1、通过git下载SDK到本地

git clone https://github.com/ks3sdk/ks3-python-sdk.git

2、进入ks3-python-sdk目录

cd  ks3-python-sdk

3、安装SDK

python setup.py install

创建一个connection(初始化）

注：（[AccessKey和SecretKey]） AWS_ACCESS_KEY_ID：金山云提供的ACCESS KEY ID

AWS_SECRET_ACCESS_KEY：金山云提供的SECRET KEY ID

from ks3.connection import Connection
ak = 'YOUR_ACCESS_KEY'
sk = 'YOUR_SECRET_KEY'
c = Connection(ak, sk, host=“kss.ksyun.com”)

备注：示例中使用的是杭州域名，若所属Region不为杭州，请更换为对应域名，域名请参见API接口文档-Region(区域)

运行环境

适用于2.6、2.7、3.3、3.4的Python版本

SDK介绍及使用

资源管理操作

Service操作

List Buckets

列出客户所有的 Bucket 信息

buckets = c.get_all_buckets()
for b in  buckets:
    print b.name

Bucket操作

Create Bucket

创建一个新的Bucket

在建立了连接后，可以创建一个bucket。bucket在s3中是一个用于储存key/value的容器。用户可以将所有的数据存储在一个bucket里，也可以为不同种类数据创建相应的bucket。

bucket_name = "YOUR_BUCKET_NAME"
b = c.create_bucket(bucket_name)

注：这里如果出现409 conflict错误，说明请求的bucket name有冲突，因为bucket name是全局唯一的

Delete Bucket

删除指定Bucket

删除一个bucket可以通过delete_bucket方法实现。

c.delete_bucket(bucket_name)

如果bucket下面存在key，那么需要首先删除所有key

b = c.get_bucket(bucket_name)
for k in b.list():
    k.delete()
c.delete_bucket(bucket_name)
Get Bucket ACL

获取Bucket的ACL

acp = b.get_acl()
>>> acp
<Policy: MTM1OTk4ODE= (owner) = FULL_CONTROL>
>>> acp.acl
<ks3.acl.ACL object at 0x23cf750>
>>> acp.acl.grants
[<ks3.acl.Grant object at 0xf63810>]
>>> for grant in acp.acl.grants:
...   print grant.permission, grant.display_name, grant.email_address, grant.id
...
Put Bucket ACL

*设置Bucket的ACL

//设置bucket的权限
b.set_acl("public-read")

Object操作

Get Object

下载该Object数据

下载object，并且作为字符串返回

from ks3.connection import Connection

bucket_name = "YOUR_BUCKET_NAME"
key_name = "YOUR_KEY_NAME"(若object放到目录下，key_name含目录前缀)
b = c.get_bucket(bucket_name)
k = b.get_key(key_name)
s = k.get_contents_as_string()
print s

下载object，并且保存到文件中

k.get_contents_to_filename("/root/KS3SDK_download_test")
Put Object

上传Object数据

将指定目录的文件上传

bucket_name = "YOUR_BUCKET_NAME"
key_name = "YOUR_KEY_NAME" (若object放到目录下，key_name含目录前缀)

b = c.get_bucket(bucket_name)
k = b.new_key(key_name)
k.set_contents_from_filename("/root/KS3SDK_upload_test")

选择添加md5参数，保证上传文件md5值正确

import hashlib
file = open("/root/KS3SDK_upload_test", 'rb')
md5 = hashlib.md5()
md5.update(file.read())
file.close()
key.set_contents_from_filename("/root/KS3SDK_upload_test", policy="public-read-write", md5=(md5.digest(), md5.digest().encode('base64')[:-1]))

将字符串所谓value上传

k.set_contents_from_string('This is a test of S3')
List Objects

列举Bucket内的Object

b = c.get_bucket(bucket_name)
keys = b.list()
Get Object ACL

获得Object的acl

b = c.get_bucket(bucket_name)
policy = b.get_acl(key_name)
print policy.to_xml()
Put Object ACL
b.set_acl("public-read", test_key)
Upload Part

分块上传

如果你想上传一个大文件，你可以将它分成几个小份，逐个上传，s3会按照顺序把它们合成一个最终的object。整个过程需要几步来完成，下面的demo程序是通过python的FileChunkIO模块来实现的。所以可能需要首先运行pip install FileChunkIO来安装。

>>> import math, os
>>> from ks3.connection import Connection
>>> from filechunkio import FileChunkIO

##  Connect to S3
>>> bucket_name = "YOUR_BUCKET_NAME"
>>> c = Connection(ak, sk)
>>> b = c.get_bucket(bucket_name)

##  Get file info
>>> source_path = 'path/to/your/file.ext'
>>> source_size = os.stat(source_path).st_size

##  Create a multipart upload request
>>> mp = b.initiate_multipart_upload(os.path.basename(source_path))

##  Use a chunk size of 50 MiB (feel free to change this)
>>> chunk_size = 52428800
>>> chunk_count = int(math.ceil(source_size / chunk_size))

##  Send the file parts, using FileChunkIO to create a file-like object
##  that points to a certain byte range within the original file. We
##  set bytes to never exceed the original file size.
>>> for i in range(chunk_count + 1):
>>>     offset = chunk_size * i
>>>     bytes = min(chunk_size, source_size - offset)
>>>     with FileChunkIO(source_path, 'r', offset=offset,
                         bytes=bytes) as fp:
>>>         mp.upload_part_from_file(fp, part_num=i + 1)

##  Finish the upload
>>> mp.complete_upload()