Adjust the Address (Solution)

Hi, why the result is not:

Cookie Cabinet
Cookie Cabinet
Cookie Cabinet

I thought that once you use the word global on line 4 of the solution code, all other two “address” variable would become like line 5. Why line 10 is not affected and line 15 is?

@taniferf It would probably help to step through the code line by line in a debugger to get an idea of what’s going on. Anyway, let’s try to use a pen-and-paper approach.

The code starts at line 13, where you define a global variable and assign an initial value to it. Then, you jump into the outer function, explore_basement(), and continue on line 8, which defines a local variable with the same name as your global variable. Due to Python’s scoping rules, this local variable shadows the global variable within the function’s scope, meaning the code will use the local version instead of the global one.

Next, you jump into another function, explore_cabinet(), which tells Python to refer to the already defined global variable instead of creating a variable local to the current function. Consequently, when you assign the value “Cookie Cabinet”, you overwrite the original value stored in the global variable. This has no effect on the variable local to the outer function.

Whenever you leave a function and return to the calling function, Python restores the local variables specific to that function. Unless you explicitly qualified a variable with the global keyword—or nonlocal, which is another story—you can generally tell the difference between global and local variables by looking at their scope, which is indicated by their indentation level.

Thanks!