A module is a part of a program. Programs are composed of one or more independently developed modules

The process of subdividing a computer program into separate sub-programs is called modular programming.

The output of the program
7
10

The output of the program
7

The LEGB rule is used to decide the order in which the scopes are to be searched for scope resolution. The scopes are listed below in terms of hierarchy (highest to lowest).

Variable are addresses (references, or pointers, to an object in memory

Python prescribes a convention of prefixing the name of the variable or method with single or double underscore to emulate the behavior of protected and private access specifiers.
Example: self_n2 = n2

Namespaces are containers for mapping names of variables to objects.
Example : a : =5
Here the variable 'a' is mapped to the value '5.

Scope should be used for a variable because; it limits a variables scope to a single definition. That is the variables are visible only to that part of the code. Essentially, variables are addresses to an object in memory. When you assign a variable with := to an instance (object), you're binding (or mapping) the variable to that instance. Multiple variables can be mapped to the same instance.

Scope refers to the visibility of variables, parameters and functions in one part of a program to another part of the same program.