What does the global keyword do in Python?

The global keyword in Python is used to declare that a variable inside a function should refer to a variable defined outside of that function, thereby indicating that its scope is global rather than local within the function. This means that when you use the global keyword, any assignment to that variable will modify the global variable rather than creating a new local variable with the same name.

When a variable is defined globally, it can be accessed and modified from within any function, provided it is declared with the global keyword when being assigned a value inside that function. This allows for greater control over variable scope and helps avoid issues associated with variable shadowing, where local variables can unintentionally overshadow global variables.

The other choices do not accurately describe the purpose of the global keyword in Python. For example, declaring a variable to be local or initializing a variable suggests different functionality than what the global keyword provides. Similarly, the notion of locking a variable's value is incorrect within the context of Python's variable handling and scope.