如何使用boto3 S3对象保存到一个文件 [英] How to save S3 object to a file using boto3

问题描述

我试图做一个Hello World新 boto3 客户端AWS。

I'm trying to do a "hello world" with new boto3 client for AWS.

用例我有相当简单：从S3获得的对象，并将其保存到文件

The use-case I have is fairly simple: get object from S3 and save it to the file.

在博托2.X我会做这样的：

In boto 2.X I would do it like this:

import boto
key = boto.connect_s3().get_bucket('foo').get_key('foo')
key.get_contents_to_filename('/tmp/foo')

在博托3。我找不到一个干净的方式做同样的事情，所以我手动遍历流的对象：

In boto 3 . I can't find a clean way to do the same thing, so I'm manually iterating over the "Streaming" object:

import boto3
key = boto3.resource('s3').Object('fooo', 'docker/my-image.tar.gz').get()
with open('/tmp/my-image.tar.gz', 'w') as f:
    chunk = key['Body'].read(1024*8)
    while chunk:
        f.write(chunk)
        chunk = key['Body'].read(1024*8)

或

import boto3
key = boto3.resource('s3').Object('fooo', 'docker/my-image.tar.gz').get()
with open('/tmp/my-image.tar.gz', 'w') as f:
    for chunk in iter(lambda: key['Body'].read(4096), b''):
        f.write(chunk)

和它工作正常。我想知道是否有任何原生boto3功能，将做同样的工作？

And it works fine. I was wondering is there any "native" boto3 function that will do the same task?

推荐答案

涡，

有一个定制最近走进宝途3，与此帮助（除其他事项外）。它是目前公开的低级别S3客户机上，并且可以用于这样的：

There is a customization that went into Boto 3 recently which helps with this (among other things). It is currently exposed on the low-level S3 client, and can be used like this:

s3_client = boto3.client('s3')
open('hello.txt').write('Hello, world!')

# Upload the file to S3
s3_client.upload_file('hello.txt', 'MyBucket', 'hello-remote.txt')

# Download the file from S3
s3_client.download_file('MyBucket', 'hello-remote.txt', 'hello2.txt')
print(open('hello2.txt').read())

这些功能将自动处理读/写文件，以及做多部分上传平行大文件。请让我知道，如果您还有其他的问题！

These functions will automatically handle reading/writing files as well as doing multipart uploads in parallel for large files. Please let me know if you have other questions!

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