Python

Modularity
Modularity refers to the concept of making multiple modules first and then linking and combining them to form a complete system
Modularity enables re-usability and will minimize duplication

Modules
Module is a file containing definitions and statements. A module can define functions, classes and variables. Modules help organize code into separate files so that programs become easier to maintain and reuse.

To create a module

def add(x, y):
    return (x+y)
print(add(2,3))
def sub(x, y):
    return (x-y)
print(sub(12,2))

Output:5
10

Types of Modules

• Built-in Modules
• User-Defined Modules
• External (Third-Party) Modules
• Package Modules

Import the module
Modules can be used in another file using the import statement

import module

import calc
print(calc.add(10, 2))

Output:12

ModuleNotFoundError
ModuleNotFoundError in Python means the interpreter cannot find the library or file you are trying to import.