code: def open(cls, filename):
          
          import boto
          file_info = cls.parse_remote(filename)
          connection = cls.connect(filename)
          try:
              s3_bucket = connection.get_bucket(file_info.bucket)
          except boto.exception.S3ResponseError as error:
              # if we don't have bucket permissions but folder permissions,
              # try without validation
              if error.status == 403:
                  s3_bucket = connection.get_bucket(file_info.bucket,
                                                    validate=False)
              else:
                  raise
  
          s3_key = s3_bucket.get_key(file_info.key)
          if s3_key is None:
              raise ValueError("Did not find S3 key: %s" % filename)
          return S3Handle(s3_key)
docs: Return a handle like object for streaming from S3.