Modules: Importing Modules, Math and Random Module, Creating your own Modules, and Concept of Packages

Module is a file containing Python code such as variables, functions, and classes that can be used in another Python program. Modules help organize code and promote code reusability.

Advantages of Modules:

1. Code reusability.
2. Better organization of programs.
3. Easier maintenance.
4. Reduces code duplication.
5. Improves readability.

Importing Modules

To use a module, it must first be imported into the program.

Syntax

import module_name

Example

import math

print(math.sqrt(25))

Output

5.0

Import Specific Functions

Syntax

from module_name import function_name

Example

from math import sqrt

print(sqrt(36))

Output

6.0

Import Multiple Functions

from math import sqrt, factorial

print(sqrt(49))
print(factorial(5))

Import Using Alias

An alias is an alternative name for a module.

Syntax

import module_name as alias_name

Example

import math as m

print(m.pi)

Output

3.141592653589793

Math Module

The math module provides mathematical functions and constants.

Importing Math Module

import math

Common Functions of Math Module

1. sqrt()

Returns the square root of a number.

import math

print(math.sqrt(64))

Output

8.0

2. pow()

Returns the power of a number.

import math

print(math.pow(2, 3))

Output

8.0

3. factorial()

Returns factorial of a number.

import math

print(math.factorial(5))

Output

120

4. ceil()

Rounds a number upward.

import math

print(math.ceil(5.2))

Output

6

5. floor()

Rounds a number downward.

import math

print(math.floor(5.8))

Output

5

Important Constants

pi

import math

print(math.pi)

Output

3.141592653589793

e

import math

print(math.e)

Output

2.718281828459045

Random Module

The random module is used to generate random numbers and random selections.

Importing Random Module

import random

1. random()

Generates a random decimal number between 0 and 1.

import random

print(random.random())

Possible Output

0.5472

2. randint()

Generates a random integer within a specified range.

import random

print(random.randint(1, 10))

Possible Output

7

3. choice()

Selects a random element from a sequence.

import random

colors = ["Red", "Blue", "Green"]

print(random.choice(colors))

Possible Output

Blue

4. shuffle()

Randomly rearranges list elements.

import random

numbers = [1, 2, 3, 4, 5]

random.shuffle(numbers)

print(numbers)

Possible Output

[4, 1, 5, 2, 3]

Creating Your Own Modules

A user can create custom modules by saving Python code in a separate .py file.

Step 1: Create a Module

Create a file named calculator.py

def add(a, b):
    return a + b

def multiply(a, b):
    return a * b

Step 2: Use the Module

Create another Python file.

import calculator

print(calculator.add(10, 20))
print(calculator.multiply(5, 4))

Output

30
20

Advantages of User Defined Modules

1. Code reusability.
2. Better organization.
3. Easier testing.
4. Simplifies large programs.

Concept of Packages

A Package is a collection of related modules organized in directories.

Packages help manage large projects efficiently.

Structure of a Package

mypackage/
│
├── module1.py
├── module2.py
├── module3.py
└── __init__.py

The __init__.py file indicates that the directory is treated as a package.

Importing Modules from a Package

Example Structure

mypackage/
│
├── calculator.py
└── __init__.py

calculator.py

def add(a, b):
    return a + b

Main Program

from mypackage import calculator

print(calculator.add(10, 5))

Output

15

Difference Between Module and Package

Summary Table