Crafting Python Modules and Packages : Your Own Modules

Python’s strength lies not only in its rich library of modules but also in the ability to create your own custom modules and packages. In this comprehensive guide, we’ll dive into the art of creating custom Python modules, providing detailed explanations, real-world examples, and practical use cases, complete with code snippets and outputs. By the end, you’ll be empowered to craft your own Python modules and enhance your code’s modularity and reusability.

Introduction to Modules

Before we delve into creating custom modules, let’s recap what a module is. In Python, a module is a file containing Python code, typically containing functions, classes, and variables, that you can import and reuse in your programs.

Creating Custom Modules

Creating a custom module is as simple as writing Python code and saving it with a .py extension. Here’s a step-by-step guide to creating your own module.

Step 1: Write Your Python Code

Write the Python code that you want to encapsulate in your module. For example, let’s create a module named my_math containing a custom function.

# my_math.py
def square(x):
    """Return the square of a number."""
    return x * x

import my_math
result = my_math.square(5)
print(result)  # Output: 25

geometry/
    __init__.py
    circle.py
    rectangle.py

# circle.py
import math
def calculate_area(radius):
    return math.pi * radius * radius

# rectangle.py
def calculate_area(length, width):
    return length * width

from geometry import circle, rectangle
circle_area = circle.calculate_area(5)
rectangle_area = rectangle.calculate_area(4, 6)
print(circle_area)    # Output: 78.53981633974483
print(rectangle_area) # Output: 24