Python Modules: Understanding, Importing, Creating Custom Modules, and Exploring math, os, and random Modules

Modules in Python

A module in Python is a file containing Python definitions and statements. It allows you to organize your code into reusable components.

Syntax:

# Importing a module
import module_name

Example:

# math module
import math
print(math.sqrt(16))  # Output: 4.0

Importing Modules

Importing modules makes functions, variables, and classes defined in them available for use in your program.

Syntax:

import module_name

Example:

import math
print(math.pi)  # Output: 3.141592653589793

What is a Custom Module?

A custom module is simply a Python file (ending in .py) that contains functions, variables, or classes that you create. This allows you to organize your code into separate files and reuse them easily.

Steps to Create and Use a Custom Module:

1. Create a Python File (Module)

First, create a Python file (e.g., my_module.py) where you define your functions or variables.

Example (my_module.py):

# This is the custom module (my_module.py)
def greet(name):
    return f"Hello, {name}!"  # Function to greet someone

def add(a, b):
    return a + b  # Function to add two numbers

2. Use the Custom Module in Another Python File

Now, you can use the functions or variables defined in my_module.py by importing it into another Python file.

Example (main.py):

# Importing the custom module
import my_module

# Using the functions from the custom module
print(my_module.greet("Alice"))  # Output: Hello, Alice!
print(my_module.add(5, 3))  # Output: 8

3. math Module

The math module provides mathematical functions, like trigonometric operations, logarithmic functions, etc.


Syntax:

import math

Example:

import math
print(math.factorial(5))  # Output: 120

4. os Module

The os module provides functions to interact with the operating system, like working with file systems, directories, and processes.

Syntax:

import os

Example:

import os
print(os.getcwd())  # Output: Current working directory

Output:

/path/to/your/directory

5. random Module

The random module is used to generate random numbers, select random items from a list, and more.

Syntax:

import random

Example:

import random
print(random.randint(1, 10))  # Output: Random number between 1 and 10

Output:

7 # (example output, could be any random number between 1 and 10)