How to tell if boto.sqs.Queue.write() succeeded?

The documentation quote you provide comes from the SQS tutorial. The SQS API docs correctly describe the current return value. The SQS tutorial is simply out of date and needs to be corrected. I have created an issue to track this.

If the write fails for any reason, the service will return an HTTP error code which, in turn, will cause boto to raise an SQSError exception. If no exception is raised, the write was successful.