Modules | nji

Python Programming For Beginners

About Lesson

Importing and Using Modules

Definition: A module is a file containing Python code (functions, classes, variables) that can be imported and used in other Python programs.
Built-in Modules: Python comes with a standard library of modules (e.g., math, os, sys). python
```
import math print(math.sqrt(16)) # Output: 4.0
```
Importing Modules:
- Entire Module: import module_name
- Specific Function/Class: from module_name import function_name
- Alias: import module_name as alias
python
```
from math import sqrt print(sqrt(16)) # Output: 4.0 import math as m print(m.sqrt(16)) # Output: 4.0
```

Creating Your Own Modules

Definition: Custom modules can be created by saving Python code in a .py file and importing it into other programs.

Example:

Create a module (my_module.py):
python

def greet(name): return f"Hello, {name}!"

Import and use the module:
python

import my_module print(my_module.greet("Alice")) # Output: Hello, Alice!