具有“拒绝访问”错误的Python S3 Amazon代码

Question

I am trying to download a specific S3 file off a server using Python Boto and am getting "403 Forbidden" and "Access Denied" error messages. It says the error is occurring at line 24 (get_contents command). I have tried it with and without the "aws s3 cp" at the start of the source file path, received the same error message both time. My code is below, any advice would be helpful.

# Code to append csv:
import csv
import boto
from boto.s3.key import Key

keyId ="key"
sKeyId="secretkey"
srcFileName="aws s3 cp s3://...."
destFileName="C:\\Users...."
bucketName="bucket00001"
conn = boto.connect_s3(keyId,sKeyId)
bucket = conn.get_bucket(bucketName, validate = False)

#Get the Key object of the given key, in the bucket
k = Key(bucket, srcFileName)
#Get the contents of the key into a file
k.get_contents_to_filename(destFileName)

Answer 1

srcFileName="aws s3 cp s3://...."

This has to be a key like somefolder/somekey or somekey as string.

You are providing a path or command to it.

Answer 2

AWS is very vague with the errors that it outputs. This is intentional, but it definitely doesn't help with debugging. You are receiving an Access Denied error because the source file name you are using is not the correct path for the file.

aws s3 cp

This is the CLI command to copy one or more files from a source to a destination (with either being an s3 bucket). This should not be apart of the source file name.

s3://...

This prefix is appended to your bucket name that denotes that the path refers to an s3 object, however, this is not necessary in your source file path name when using boto3.

To download an s3 file using boto3, perform the following:

import boto3

BUCKET_NAME = 'my-bucket' # does not include s3://
KEY = 'image.jpg' # the file you want to download

s3 = boto3.resource('s3')
s3.Bucket(BUCKET_NAME).download_file(KEY, 'image.jpg')

Documentation for this command can be found here: https://boto3.readthedocs.io/en/latest/guide/s3-example-download-file.html

In general, boto3 (and any other AWS SDK's) are simply wrappers around AWS api requests. You can also use the aws cli like I mentioned earlier to download a file from s3. That command would be:

aws s3 cp s3://my-bucket/my-file.jpg C:\location\my-file.jpg