What is the purpose of the global keyword?

• A. It is used to create new variables
• B. It is used to declare a variable as global, allowing modifications to it inside a function
• C. It enhances function security
• D. It defines a variable scope only within a class

Answer: (B)

The global keyword allows you to declare a variable as global, which grants the ability to modify it inside a function that would normally create a new local variable with the same name. When a variable is declared as global, Python understands that you are referring to the variable defined at the module level, rather than creating a new one locally. This capability is particularly useful when you need to change the value of a global variable from within a function, ensuring that any updates are reflected throughout the program.

For example, without the global keyword, any assignment to a variable that shares the same name as a global variable would be treated as a local variable that only exists within the function's scope. By using global, you clarify your intent and maintain the linkage to the larger scoped variable.

This understanding is foundational in managing variable scopes in Python programming, especially in situations where you need to coordinate between different functions and maintain a consistent state across them.