a method to retrieve a list of buckets on s3

        :return: list of buckets

def list_buckets(self):

        '''
            a method to retrieve a list of buckets on s3

        :return: list of buckets
        '''

        title = '%s.list_buckets' % self.__class__.__name__
        
        bucket_list = []
        
    # send request to s3
        try:
            response = self.connection.list_buckets()
        except:
            raise AWSConnectionError(title)

    # create list from response
        for bucket in response['Buckets']:
            bucket_list.append(bucket['Name'])

        self.bucket_list = bucket_list
        
        return self.bucket_list