Scopes

Lesson

A “scope” is what defines the lifetime of a variable.
Let’s take a function as an example.

def Bar():
    i = 5

print(i)

This program will not work, because the variable i is defined in the function scope, and is not available elsewhere.\

In Python, scopes are defined as indentations.
Every time a new scope is created, we had a space before each line.
Instructions in the same scope should all be aligned together.
They are also preceded by “:”.

In other languages, indentation and spaces are ignored.
This is similar to the Execution Order chapter.
Scopes are defined with brackets.
The instructions of a given scope are surrounded by { and }.

void Bar()
{ // scope begins
    int i = 5; 
} // scope ends

Even if indentation is not forced, it is a good practice to do it for readability.

You will see in the following chapters that scopes can be used for other things than functions.