Python Modules
A module in Python is simply a file that groups related code together. Think of it as a reusable toolbox that can contain functions, variables, and even classes. By organizing code into modules, your programs become cleaner, easier to maintain, and reusable across multiple projects.
In practice, any Python file with a .py extension can act as a
module.
Creating Your Own Module
To create a module, write your Python code in a file and save it with a
.py extension.
Example: create a file named utils.py
Using a Module
Once a module is created, you can use it in another Python file with the
import statement.
Example: importing and using the module
When calling something from a module, always use the format:
module_name.member_name.
Variables Inside a Module
Modules are not limited to functions—they can also store variables such as lists, dictionaries, or constants.
Example: update utils.py
Accessing module variables
Naming Rules for Modules
- Module names can be anything meaningful
-
The file must end with
.py - Avoid using Python reserved keywords
Using an Alias for a Module
Sometimes module names are long or conflict with other names. Python allows
you to rename them during import using as.
Example: module aliasing
Built-in Python Modules
Python ships with many built-in modules that provide ready-made functionality, such as working with the OS, math operations, or system information.
Example: using the datetime module
Exploring a Module with dir()
The dir() function helps you inspect what functions and
variables are available inside a module.
Example: listing members of a module
This works for both built-in modules and user-defined modules.
Importing Specific Members from a Module
If you only need certain parts of a module, you can import them directly
using the from keyword.
Example: module content
Import only what you need
When using from module import name, you can access the name
directly without the module prefix.
