Sample Python Code Using DreamObjects S3-compatible API And Boto

This article lists several Python code examples to interact with DreamObjects.

Creating a Connection

Create a connection so you can interact with the server.

import boto
import boto.s3.connection
access_key = 'put your access key here!'
secret_key = 'put your secret key here!'

conn = boto.connect_s3(
    aws_access_key_id = access_key,
    aws_secret_access_key = secret_key,
    host = '',
    calling_format = boto.s3.connection.OrdinaryCallingFormat(),

Listing Owned Buckets

Get a list of Buckets you own. This also prints out the bucket name and creation date of each bucket.

for bucket in conn.get_all_buckets():
    print "{name}\t{created}".format(
        name =,
        created = bucket.creation_date,

The output will look something like this:

mahbuckat1   2011-04-21T18:05:39.000Z
mahbuckat2   2011-04-21T18:05:48.000Z
mahbuckat3   2011-04-21T18:07:18.000Z

Creating a Bucket

Create a new bucket called my-new-bucket.

bucket = conn.create_bucket('my-new-bucket')

Listing a Bucket’s Content

Get a list of objects in the bucket. This also prints out each object’s name, the file size, and last modified date.

for key in bucket.list():
    print "{name}\t{size}\t{modified}".format(
        name =,
        size = key.size,
        modified = key.last_modified,

The output will look something like this:

myphoto1.jpg 251262  2011-08-08T21:35:48.000Z
myphoto2.jpg 262518  2011-08-08T21:38:01.000Z

Deleting a Bucket

The Bucket must be empty, otherwise it won’t work.


Forced Delete for Non-empty Buckets

not available in python

Creating an Object

Create a file hello.txt with the string "Hello World!"

key = bucket.new_key('hello.txt')
key.set_contents_from_string('Hello World!')

Change an Object’s ACL

Make the object hello.txt publicly readable and secret_plans.txt to be private.

hello_key = bucket.get_key('hello.txt')
plans_key = bucket.get_key('secret_plans.txt')

Download an Object (to a file)

Download the object perl_poetry.pdf and save it in /home/larry/documents/.

key = bucket.get_key('perl_poetry.pdf')

Delete an Object

Delete the object goodbye.txt.


Generate Object Download URLs (signed and unsigned)

This generates an unsigned download URL for hello.txt. This works because hello.txt was made public by setting the ACL above. This then generates a signed download URL for secret_plans.txt that will work for 1 hour. Signed download URLs will work for the time period even if the object is private (when the time period is up, the URL will stop working).

hello_key = bucket.get_key('hello.txt')
hello_url = hello_key.generate_url(0, query_auth=False, force_http=True)
print hello_url

plans_key = bucket.get_key('secret_plans.txt')
plans_url = plans_key.generate_url(3600, query_auth=True, force_http=True)
print plans_url

The output of this will look something like:

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Article last updated PST.