🐍 Python Tutorial: Modules and Packages

As your Python programs grow in size and complexity, it's useful to organize your code into reusable files called modules, and directories of modules called packages. This helps keep code maintainable, reusable, and readable.

1. What is a Module?

A module is simply a Python file (.py) that contains functions, classes, or variables. You can import and use them in other files.

# greetings.py

def say_hello(name):
  print(f"Hello, {name}!")

# main.py
import greetings

greetings.say_hello("Alice")

2. What is a Package?

A package is a directory that contains a special __init__.py file (can be empty) and one or more module files.

# directory structure:
my_package/
├── __init__.py
├── math_utils.py
├── string_utils.py

You can import functions from modules inside a package:

from my_package.math_utils import add
result = add(2, 3)

3. Built-in Modules

Python comes with many useful standard modules like math, random, datetime, and more.

import math
print(math.sqrt(16))  # 4.0

4. Installing Third-Party Packages

Use pip to install external packages:

pip install requests

Then import and use them in your script:

import requests
response = requests.get("https://api.github.com")
print(response.status_code)

Additional Resources & References