give me a example about how to describe_replication_tasks api in boto3 by python

Sure, I can help you with that!

The describe_replication_tasks API in boto3 is used to retrieve information about AWS DMS replication tasks. Here's an example code snippet in Python using boto3:

import boto3

# Create DMS client
dms = boto3.client('dms')

# Describe replication tasks
response = dms.describe_replication_tasks(
    Filters=[
        {
            'Name': 'replication-task-arn',
            'Values': [
                'arn:aws:dms:us-west-2:123456789012:task:my-task',
            ]
        },
    ]
)

# Display replication tasks information
for task in response['ReplicationTasks']:
    print(f"Task ARN: {task['ReplicationTaskArn']}")
    print(f"Task Status: {task['Status']}")

In this example, we first create a DMS client using boto3. Then, we use the `describe_replication_tasks` API to retrieve information about a specific replication task (in this case, with the ARN `arn:aws:dms:us-west-2:123456789012:task:my-task`). Finally, we loop through the response and print out the task's ARN and status.

I hope this helps! Let me know if you have any further questions.