Reference:
https://www.cisco.com/c/en/us/support/docs/security/email-security-appliance/118219-configure-esa-00.html

Explanation Cisco Email Security Appliance (ESA) protects the email infrastructure and employees who use email at work by filtering unsolicited and malicious email before it reaches the user. Cisco ESA easily integrates into existing email infrastructures with a high degree of flexibility. It does this by acting as a Mail Transfer Agent (MTA) within the email-delivery chain. Another name for an MTA is a mail relay. Reference: https://www.cisco.com/c/dam/en/us/td/docs/solutions/SBA/February2013/ Cisco_SBA_BN_EmailSecurityUsingCiscoESADeploymentGuide-Feb2013.pdf Cisco Email Security Appliance (ESA) protects the email infrastructure and employees who use email at work by filtering unsolicited and malicious email before it reaches the user. Cisco ESA easily integrates into existing email infrastructures with a high degree of flexibility. It does this by acting as a Mail Transfer Agent (MTA) within the email-delivery chain. Another name for an MTA is a mail relay.
Reference:
Explanation Cisco Email Security Appliance (ESA) protects the email infrastructure and employees who use email at work by filtering unsolicited and malicious email before it reaches the user. Cisco ESA easily integrates into existing email infrastructures with a high degree of flexibility. It does this by acting as a Mail Transfer Agent (MTA) within the email-delivery chain. Another name for an MTA is a mail relay. Reference: https://www.cisco.com/c/dam/en/us/td/docs/solutions/SBA/February2013/ Cisco_SBA_BN_EmailSecurityUsingCiscoESADeploymentGuide-Feb2013.pdf

The Python script of the Cisco DNA Center API in the exhibit uses the requests module to send a GET request to the /dna/intent/api/v1/network-device endpoint, which returns a list of network devices managed by Cisco DNA Center. The script also uses HTTPBasicAuth to provide the username and password for authentication. The script then parses the JSON response and prints the hostname, type, management IP address, and software version of each device in a table format using the prettytable module. Therefore, the result of this script is to receive information about a switch or switches from Cisco DNA Center. References:
* Python Scripting APIs in Cisco DNA Center Let You Improve Effectiveness, Topic: Network device's script, simple and easy to create
* Intro to Cisco DNA Center REST API with Python, Module 2: Using Python to Retrieve a Network Device List
* Cisco DNA Center API Call Python Script Example, Topic: Cisco DNA CENTER SANDBOX Call DNA Center API Call Python Script Example