April Python Bootcamp Day 13

 

What is a Module?

A module is a single Python file (.py) that contains functions, variables, or classes which can be reused in other programs.

Example:
If you create a file named utils.py, it becomes a module.

Why modules are important:

• Promote code reusability
• Help in organizing large codebases
• Reduce redundancy

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What is a Package?

A package is a folder that contains multiple modules.

Structure example:

my_package/
    ├── module1.py
    ├── module2.py
    └── __init__.py

Packages allow you to structure your project logically and scale your code efficiently.

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Importing Modules

There are multiple ways to import modules:

1. Import Entire Module

import math
print(math.sqrt(16))

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2. Import Specific Functions

from math import sqrt, ceil

print(sqrt(16))
print(ceil(4.2))

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3. Using Module Alias

import math as m
print(m.factorial(5))

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Built-in Modules in Python

Python provides many built-in modules that simplify development.

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Math Module

Used for mathematical operations.

import math

print(math.sqrt(16))
print(math.ceil(4.2))
print(math.floor(4.9))
print(math.pow(2, 3))
print(math.factorial(5))

Common functions:

• sqrt()
• ceil()
• floor()
• pow()
• factorial()

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Random Module

Used for generating random values.

import random

print(random.random())
print(random.randint(1, 10))
print(random.choice([1, 2, 3, 4]))

Shuffling example:

lst = [1, 2, 3, 4]
random.shuffle(lst)
print(lst)

Other function:

• uniform(a, b) → random float between a and b

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Datetime Module

Used for working with dates and time.

from datetime import datetime, date, timedelta

print(datetime.now())
print(date.today())

d = datetime.now()
print(d.strftime("%Y-%m-%d"))

new_date = d + timedelta(days=5)
print(new_date)

Key functionalities:

• Current date and time
• Formatting dates
• Date arithmetic

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OS Module

Used for interacting with the operating system.

import os

print(os.getcwd())
print(os.listdir())

Common operations:

• Get current directory
• List files
• Create/delete folders
• Rename files

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Key Takeaways

• Modules help reuse code
• Packages help organize large projects
• Built-in modules save development time
• Proper imports improve code readability

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Assignment Questions

Basic Level

1. Import the math module and find square root of a number
2. Import specific functions from math and use ceil() and floor()
3. Generate a random number between 1 and 50
4. Print current date using datetime
5. Print current working directory using os

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Intermediate Level

1. Generate a list of 5 random numbers using random.randint()
2. Shuffle a list of numbers using random.shuffle()
3. Format current date as DD-MM-YYYY
4. Create a program to add 7 days to current date
5. List all files in your current directory

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Advanced Level

1. Create your own module with functions (e.g., add, subtract) and import it
2. Create a package with at least 2 modules and use them
3. Build a mini project using math and random (e.g., number guessing game)
4. Write a script to organize files in a folder using os
5. Combine datetime and os to log file creation time

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Summary

Modules and packages are fundamental for writing scalable Python applications.

• Modules allow code reuse
• Packages provide structure
• Built-in modules handle complex operations easily

Understanding this concept is essential before moving into:

• Large projects
• Frameworks
• Real-world software development