Variables & Their Types

In Python, variables are an important part of programming. A variable defines a location in memory to store any data. Variables in Python can be classified into two types: local and global. This classification is based on where and in which scope the variable is declared.

We can understand variables as a place that is used to store specific data in the computer's memory. When we need that data in a program, we can access it by giving the variable's name.

1. Local Variable: A local variable is a variable that is defined inside a function or block. The scope of such variables is limited to only that function or block in which they are defined.

2. Global Variable: A global variable is a variable that is defined outside a function and can be accessed anywhere throughout the program.

If we need to change the value of a global variable inside a function, we have to use the `global` keyword.

In Python, nested functions can be defined inside other functions. In such cases, we use the `nonlocal` keyword to refer to a variable that is neither local nor global.