Get publicly accessible contents of S3 bucket without AWS credentials
If the bucket's permissions allow Everyone to list it, you can just do a simple HTTP GET request to http://s3.amazonaws.com/bucketname with no credentials. The response will be XML with everything in it, whether those objects are accessible by Everyone or not. I don't know if boto has an option to make this request without credentials. If not, you'll have to use lower-level HTTP and XML libraries.
If the bucket itself does not allow Everyone to list it, there is no way to get a list of its contents, even if some of the objects in it are publicly accessible.
Given a bucket with publicly accessible contents, how can I get a listing of all those publicly accessible contents? I know boto can do this, but boto requires AWS credentials. Also, boto doesn't work in Python3, which is what I'm working with.