A Python vulnerability scanner for XSS and SQL injection plays a critical role in proactively identifying and addressing security weaknesses in web applications. The scanner automates the process of examining web pages, searching for patterns indicative of XSS and SQL injection vulnerabilities, and reporting potential risks. In the context of XSS, the scanner injects carefully crafted scripts into user inputs and assesses whether the application reflects or stores these scripts, exposing vulnerabilities that could lead to unauthorized script execution in users' browsers. For SQL injection, the scanner manipulates parameters in web application SQL queries with specially designed payloads, aiming to unveil vulnerabilities that might permit unauthorized access or manipulation of the underlying database.