Mastering Python: Closures and Decorators

In this code, there are three nested functions: first_outer(), second_outer(), and inner(). Each function creates its own local scope. The non-local scope, also known as the enclosing scope, is a concept that allows inner functions to access variables from their immediate outer function's scope, but not from the global scope.

Let's break down the code and examine the non-local scope interactions:

1. first_outer() function:
- Creates a local variable first with the value "first_outer() local scope".
- Calls the second_outer() function.


2. second_outer() function:
- Creates a local variable second with the value "second_outer() local scope".
- Calls the inner() function.


3. inner() function:
- Creates a local variable third with the value "inner() local scope".
- Attempts to access the variables first and second, which are not directly defined within its local scope.

Since inner() cannot find first and second in its local scope, it looks in its non-local scope, which is the immediate outer function's scope (second_outer() in this case). It successfully finds and accesses both first and second from the non-local scopes of second_outer() and first_outer() respectively.

In this code, we have two functions: outer() and inner(). The variable some_variable is defined in the outer() function's local scope. The inner() function is nested inside the outer() function.

The nonlocal keyword is used inside the inner() function to indicate that the variable some_variable is not a local variable of inner() or global but belongs to its non-local scope (outer() in this case). This allows inner() to access and modify the non-local variable some_variable.

When we call the inner() function, it prints the value of some_variable, which is 255. Then, it increments the value of some_variable by 233, resulting in some_variable being 488.

Therefore, the nonlocal keyword allows us to modify non-local variables, just like the global keyword allows us to modify global variables from within a function's local scope.