Functions and Modules

In any program, some parts of code may need to be reused. Python offers functions and modules to help us organize and reuse code in a clean and manageable way.

What is a Function?

A function is a block of code that performs a specific task. It runs only when it is called.

Why use functions?

• To avoid repeating code
• To organize your program better
• To make your code more readable and reusable

Function with Parameters

Functions can accept parameters (inputs) and return values.

Default and Keyword Arguments

You can give a default value to a parameter.

You can also use keyword arguments:

Return Statement

Functions can return a value using return.

What is a Module?

A module is simply a Python file that contains functions, variables, or classes. You can use a module in another file using the import keyword.

Using Built-in Modules

Example: Using the math module

Creating Your Own Module

Suppose you have a file named mymodule.py:

Then in another file:

Using from Keyword

You can import specific functions:

Summary

• Use functions to reuse and organize your code.
• Functions can take parameters and return values.
• A module is a file that contains Python code.
• Use import to use code from other modules.
• Python has many built-in modules (like math, random, etc.)