An SNS topic can be created by invoking the create_topic() function of the sns_client object. The result is the Python dictionary that represents the SNS topic. Once an SNS topic is created, AWS automatically assigns a unique ARN to the topic. This ARN can be fetched using the TopicARN key of the SNS topic.

The following Python program demonstrates the creation of an SNS topic:

import boto3

# Create an SNS client object
sns_client = boto3.client(
    "sns",
   # You may have to set the AWS credentials of you haven't already set using AWS CLI
   # aws_access_key_id="YOUR ACCES KEY",   
   # aws_secret_access_key="YOUR SECRET KEY",
   # region_name=us-east-1
)

# Create an SNS topic
sns_topic = sns_client.create_topic(Name="packt-pub")
topic_arn = sns_topic['TopicArn']        # fetch the resource name

Once a topic is created, subcribers can be added to the topic using their email ID or phone number.