Lesson 7 - Modules And Packages

7.1 What Are Modules And Packages

Modules and packages in Python are fundamental for organizing and reusing code effectively.

Modules: Modules are individual Python files that contain reusable code. They allow you to logically organize your Python code into separate files. Each module can contain functions, classes, and variables that can be imported and used in other Python scripts or modules.

For example, you can have a module named utils.py that contains utility functions like read_file(), write_file(), etc. These functions can then be imported into other Python scripts to avoid rewriting the same code.

Packages: Packages are directories that contain multiple Python modules and an __init__.py file. They provide a way to structure Python's module namespace by using "dotted module names". This hierarchical structure helps in organizing and managing large Python projects more efficiently.

For instance, you could have a package named my_package which contains submodules or sub-packages like my_package.utils, my_package.models, etc. Each submodule or package within my_package can contain its own Python files (*.py) that contribute to a specific aspect of the overall functionality.

Built-in Modules: Python comes with a rich standard library that includes built-in modules such as os, sys, datetime, random, json, and re. These modules provide implementations of commonly used functionalities, ranging from interacting with the operating system (os and sys) to handling dates and times (datetime), working with JSON data (json), and performing regular expression operations (re).

Using built-in modules allows you to leverage existing solutions and focus on developing the specific logic unique to your application, thereby promoting code organization, reusability, and maintainability.