SOUNotes

IWSD Lab Manual

Practical 01

Aim: Python Program to Find Factorial of Number Using Function.

Description: This program defines a function to calculate the factorial of a given number using recursion or iteration. The user inputs a number, and the function returns its factorial.

Code:

def factorial(n):
    result = 1
    for i in range(1, n + 1):
        result *= i
    return result
 
num = int(input("Enter a number: "))
print("Factorial of", num, "is", factorial(num))

Output:

Enter a number: 5
Factorial of 5 is 120

Post Practical Questions:

Conclusion: In this practical, we implemented a function to calculate the factorial of a number using iteration. The program successfully computes the factorial for any positive integer entered by the user.

Practical 02

Aim: Develop programs to learn the concept of function scoping, recursion, and list mutability.

Description: This program demonstrates function scoping by defining and using local and global variables inside a function. It also includes an example of recursion and how lists behave when passed as function arguments.

Code:

# Function Scoping Example
x = 10  # Global variable
 
def scope_example():
    x = 5  # Local variable
    print("Inside function, x =", x)
 
scope_example()
print("Outside function, x =", x)
 
# Recursion Example (Factorial)
def factorial(n):
    if n == 0 or n == 1:
        return 1
    return n * factorial(n - 1)
 
print("Factorial of 5 is", factorial(5))
 
# List Mutability Example
def modify_list(lst):
    lst.append(4)
 
numbers = [1, 2, 3]
modify_list(numbers)
print("Modified list:", numbers)

Output:

Inside function, x = 5
Outside function, x = 10
Factorial of 5 is 120
Modified list: [1, 2, 3, 4]

Post Practical Questions:

Which of the following behaviors are associated with list mutability in Python?
- D
What happens when you modify a list inside a function in Python?
- The original list gets modified since lists are mutable and passed by reference.
What is the difference between local and global variables in the context of function scoping?
- Local variables exist only inside a function, while global variables exist throughout the program.

What will be the output of this code? Explain why:

my_list = [1, 2, 3]
def modify(lst):
    lst += [4, 5]
modify(my_list)
print(my_list)

Answer:
Output: [1, 2, 3, 4, 5]
Explanation: lst += [4, 5] modifies the original list since lists are mutable.

Conclusion: This practical demonstrated function scoping with local and global variables, recursion using a factorial function, and list mutability by modifying a list inside a function.

Practical 03

Aim: Develop programs to understand the working of exception handling and assertions.

Description: This program demonstrates exception handling by catching division by zero and invalid input errors. It also includes an assertion example.

Code:

def divide_numbers():
    try:
        a = int(input("Enter numerator: "))
        b = int(input("Enter denominator: "))
        result = a / b
        print("Result:", result)
    except ZeroDivisionError:
        print("Error: Cannot divide by zero!")
    except ValueError:
        print("Error: Invalid input! Please enter numbers.")
    finally:
        print("Execution completed.")
 
divide_numbers()

Output:

Enter numerator: 10
Enter denominator: 2
Result: 5.0
Execution completed.

Enter numerator: 5
Enter denominator: 0
Error: Cannot divide by zero!
Execution completed.

Enter numerator: abc
Error: Invalid input! Please enter numbers.
Execution completed.

Post-Practical Questions

Which of the following is true about exception handling in Python?
- b
What is the purpose of the try block in Python?
- The try block executes code that might raise an exception, ensuring errors are handled in the except block to prevent crashes.
Write a Python statement that uses assert to ensure a variable x is non-negative.
- assert x >= 0, "x must be non-negative"

Conclusion: Implemented exception handling using try, except, and finally to handle division errors and invalid inputs, and used assertions to enforce conditions in the program.

Practical 04

Aim:
Create a Web Database Application "Address Book" with options to:
a) Add/Insert a record
b) Modify a record
c) Display a record
d) Delete a record

Description:
Create a web-based "Address Book" application that allows users to add, modify, display, and delete contact records in a database using Django.

Code:

Step 1: Install Django

pip install django

Step 2: Create Project & App

django-admin startproject address_book_project
cd address_book_project
django-admin startapp address_book_app

Add 'address_book_app' to INSTALLED_APPS in settings.py.

Step 3: Models (models.py)

from django.db import models
 
class Contact(models.Model):
    name = models.CharField(max_length=100)
    phone = models.CharField(max_length=15)

Run migrations:

python manage.py makemigrations
python manage.py migrate

Step 4: Forms (address_book_app\forms.py)

from django import forms
from .models import Contact
 
class ContactForm(forms.ModelForm):
    class Meta:
        model = Contact
        fields = ['name', 'phone']

Step 5: Views (views.py)

from django.shortcuts import render, redirect, get_object_or_404
from .models import Contact
from .forms import ContactForm
 
def home(request):
    if request.method == "POST":
        form = ContactForm(request.POST)
        if form.is_valid():
            form.save()
            return redirect('home')
    else:
        form = ContactForm()
    contacts = Contact.objects.all()
    return render(request, 'home.html', {'form': form, 'contacts': contacts})
 
def update_contact(request, id):
    contact = get_object_or_404(Contact, id=id)
    if request.method == "POST":
        form = ContactForm(request.POST, instance=contact)
        if form.is_valid():
            form.save()
            return redirect('home')
    else:
        form = ContactForm(instance=contact)
    return render(request, 'update.html', {'form': form})
 
def delete_contact(request, id):
    Contact.objects.filter(id=id).delete()
    return redirect('home')

Step 6: URLs (urls.py)

from django.contrib import admin
from django.urls import path
from address_book_app import views
 
urlpatterns = [
    path('admin/', admin.site.urls),
    path('', views.home, name='home'),
    path('update/<int:id>/', views.update_contact, name='update_contact'),
    path('delete/<int:id>/', views.delete_contact, name='delete_contact'),
]

Step 7: Templates

templates/home.html

<!DOCTYPE html>
<html>
  <head>
    <title>Address Book</title>
  </head>
  <body>
    <h2>Address Book</h2>
    <form method="post">
      {% csrf_token %} {{ form.as_p }}
      <button type="submit">Add</button>
    </form>
    <ul>
      {% for c in contacts %}
      <li>
        {{ c.name }} - {{ c.phone }}
        <a href="{% url 'update_contact' c.id %}">Edit</a> |
        <a href="{% url 'delete_contact' c.id %}">Delete</a>
      </li>
      {% endfor %}
    </ul>
  </body>
</html>

templates/update.html

<!DOCTYPE html>
<html>
  <head>
    <title>Update Contact</title>
  </head>
  <body>
    <h2>Update Contact</h2>
    <form method="post">
      {% csrf_token %} {{ form.as_p }}
      <button type="submit">Update</button>
    </form>
  </body>
</html>

Step 8: Run the Server

python manage.py runserver

Output:
The browser will display the Address Book, where users can add, update, display, and delete contacts.

Post Practical Questions:

What is the role of models.py in Django?
- models.py defines the structure of the database by creating models that map to database tables. It allows interaction with the database using Django’s ORM.
What is the default database engine used by Django?
- c) SQLite
Which function is used in Django to redirect to another URL?
- a) redirect()

Conclusion:
A simple Django Address Book application was created, allowing users to add, modify, display, and delete contacts using Django models, views, and templates.

Practical 05

Aim: Create a Web Database Application "Event Registration" with options to:
a) Event Registration
b) Cancel Registration
c) Display a record

Description: Create a web-based "Event Registration" application that allows users to register for an event, cancel their registration, and display their registration details using Django.

Code:

Step 1: Install Django

pip install django

Step 2: Create Project & App

django-admin startproject event_registration_project
cd event_registration_project
django-admin startapp event_registration_app

Add 'event_registration_app' to INSTALLED_APPS in settings.py.

Step 3: Models (models.py)

from django.db import models
 
class Registration(models.Model):
    name = models.CharField(max_length=100)
    email = models.EmailField(unique=True)
    event_name = models.CharField(max_length=200)

Run migrations:

python manage.py makemigrations
python manage.py migrate

Step 4: Forms (forms.py)

from django import forms
from .models import Registration
 
class RegistrationForm(forms.ModelForm):
    class Meta:
        model = Registration
        fields = ['name', 'email', 'event_name']

Step 5: Views (views.py)

from django.shortcuts import render, redirect, get_object_or_404
from .models import Registration
from .forms import RegistrationForm
 
def home(request):
    if request.method == "POST":
        form = RegistrationForm(request.POST)
        if form.is_valid():
            form.save()
            return redirect('home')
    else:
        form = RegistrationForm()
    registrations = Registration.objects.all()
    return render(request, 'home.html', {'form': form, 'registrations': registrations})
 
def cancel_registration(request, id):
    Registration.objects.filter(id=id).delete()
    return redirect('home')

Step 6: URLs (urls.py)

from django.contrib import admin
from django.urls import path
from event_registration_app import views
 
urlpatterns = [
    path('admin/', admin.site.urls),
    path('', views.home, name='home'),
    path('cancel/<int:id>/', views.cancel_registration, name='cancel_registration'),
]

Step 7: Templates

home.html

<!DOCTYPE html>
<html>
  <head>
    <title>Event Registration</title>
  </head>
  <body>
    <h2>Event Registration</h2>
    <form method="post">
      {% csrf_token %} {{ form.as_p }}
      <button type="submit">Register</button>
    </form>
    <ul>
      {% for r in registrations %}
      <li>
        {{ r.name }} - {{ r.event_name }}
        <a href="{% url 'cancel_registration' r.id %}">Cancel</a>
      </li>
      {% endfor %}
    </ul>
  </body>
</html>

Step 8: Run the Server

python manage.py runserver

Output: The browser will display the Event Registration system, where users can register for events, view their registrations, and cancel them.

Post Practical Questions:

What is the purpose of an Event Registration Web Application?
- The purpose is to allow users to register for events, view registered participants, and cancel their registrations.
Which Django feature is used to store event registration data?
- c) Models
Which of the following is used to display all registered participants in Django?
- b) Model.objects.all()

Conclusion: A simple Django app for event registration was created, allowing users to register, view, and cancel registrations.

Practical 06

Aim: A simple "Hello World" application using Django.

Description: Create a simple Django application that displays "Hello, World!" by setting up a view, mapping it to a URL, and running the Django development server to view the output.

Code:

Step 1: Install Django

pip install django

Step 2: Create Project & App

django-admin startproject hello_world_project
cd hello_world_project
django-admin startapp hello_world_app

Add 'hello_world_app' to INSTALLED_APPS in settings.py.

Step 3: Views (views.py)

from django.http import HttpResponse
 
def hello_world(request):
    return HttpResponse("Hello, World!")

Step 4: URLs (urls.py)

hello_world_project/urls.py

from django.contrib import admin
from django.urls import path
from hello_world_app import views
 
urlpatterns = [
    path('admin/', admin.site.urls),
    path('', views.hello_world, name='hello_world'),
]

Step 5: Run the Server

python manage.py runserver

Output: The browser will display "Hello, World!" when you navigate to http://127.0.0.1:8000/.

Post Practical Questions:

Which of the following is true about Django views?
- a) Views handle HTTP requests and responses.
What is the purpose of urlpatterns in Django?
- urlpatterns is a list of URL patterns that Django uses to map incoming HTTP requests to the appropriate view functions. It defines which view should handle which URL.
How do you start a Django development server?
- To start the Django development server, use the following command in the terminal from your project directory python manage.py runserver his will start the server on http://127.0.0.1:8000/ by default.

Conclusion: A simple Django application was created to display "Hello, World!" by setting up a view and mapping it to a URL.

Practical 07

Aim: Create an extension or module library in Python to implement a Calculator.

Description: Create a Python module or extension that implements a calculator with basic operations such as addition, subtraction, multiplication, and division, providing reusable functions for each operation.

Code:

Create a Python module (calculator.py)
Create a file called calculator.py that contains the following code for basic operations:

# calculator.py
 
def add(a, b):
    return a + b
 
def subtract(a, b):
    return a - b
 
def multiply(a, b):
    return a * b
 
def divide(a, b):
    if b == 0:
        return
    return a / b

Use the Calculator Module in Another Script

# main.py
import calculator
 
# Example usage of the calculator module
 
a = 10
b = 5
 
print(f"{a} + {b} = {calculator.add(a, b)}")
print(f"{a} - {b} = {calculator.subtract(a, b)}")
print(f"{a} * {b} = {calculator.multiply(a, b)}")
print(f"{a} / {b} = {calculator.divide(a, b)}")

Run the Main Script
Run the script in the terminal:

python main.py

Output:

10 + 5 = 15
10 - 5 = 5
10 * 5 = 50
10 / 5 = 2.0

Post Practical Questions:

What is the purpose of a Python module?
- A Python module is a file that contains reusable code, functions, and variables which can be imported and used in other Python scripts.
How do you import a Python module?
- You can import a Python module using the import keyword, like this : import module_name
What happens when you divide a number by zero in Python?
- Dividing by zero in Python raises a ZeroDivisionError exception.

Conclusion: A reusable Python module calculator.py was created to perform basic operations like addition, subtraction, multiplication, and division, and was tested in another script.

Practical 08

Aim: Create an online registration web page for a Youth Festival and apply Database CRUD operations in Django Framework.

Description: Develop a Django-based registration system where users can register for the Youth Festival, view their details, update their information, and delete their registrations using Create, Read, Update, Delete (CRUD) operations.

Code:

Step 1: Install Django

pip install django

Step 2: Create Project & App

django-admin startproject youth_festival
cd youth_festival
django-admin startapp festival_app

Add 'festival_app' to INSTALLED_APPS in settings.py.

Step 3: Models (models.py)

from django.db import models
 
class Registration(models.Model):
    name = models.CharField(max_length=100)
    email = models.EmailField(unique=True)
    phone = models.CharField(max_length=15)
    event = models.CharField(max_length=100)
 
    def __str__(self):
        return self.name

Run migrations:

python manage.py makemigrations
python manage.py migrate

Step 4: Forms (forms.py)

from django import forms
from .models import Registration
 
class RegistrationForm(forms.ModelForm):
    class Meta:
        model = Registration
        fields = ['name', 'email', 'phone', 'event']

Step 5: Views (views.py)

from django.shortcuts import render, redirect, get_object_or_404
from .models import Registration
from .forms import RegistrationForm
 
def home(request):
    registrations = Registration.objects.all()
    return render(request, 'home.html', {'registrations': registrations})
 
def register(request):
    if request.method == "POST":
        form = RegistrationForm(request.POST)
        if form.is_valid():
            form.save()
            return redirect('home')
    else:
        form = RegistrationForm()
    return render(request, 'register.html', {'form': form})
 
def update_registration(request, id):
    registration = get_object_or_404(Registration, id=id)
    if request.method == "POST":
        form = RegistrationForm(request.POST, instance=registration)
        if form.is_valid():
            form.save()
            return redirect('home')
    else:
        form = RegistrationForm(instance=registration)
    return render(request, 'register.html', {'form': form})
 
def delete_registration(request, id):
    Registration.objects.filter(id=id).delete()
    return redirect('home')

Step 6: URLs (urls.py)

from django.contrib import admin
from django.urls import path
from festival_app import views
 
urlpatterns = [
    path('admin/', admin.site.urls),
    path('', views.home, name='home'),
    path('register/', views.register, name='register'),
    path('update/<int:id>/', views.update_registration, name='update_registration'),
    path('delete/<int:id>/', views.delete_registration, name='delete_registration'),
]

Step 7: Templates

home.html

<!DOCTYPE html>
<html>
  <head>
    <title>Youth Festival Registration</title>
  </head>
  <body>
    <h2>Registered Participants</h2>
    <a href="{% url 'register' %}">Register for Event</a>
    <ul>
      {% for reg in registrations %}
      <li>
        {{ reg.name }} - {{ reg.email }} - {{ reg.phone }} - {{ reg.event }}
        <a href="{% url 'update_registration' reg.id %}">Edit</a>
        <a href="{% url 'delete_registration' reg.id %}">Delete</a>
      </li>
      {% endfor %}
    </ul>
  </body>
</html>

register.html

<!DOCTYPE html>
<html>
  <head>
    <title>Register for Youth Festival</title>
  </head>
  <body>
    <h2>Register for Youth Festival</h2>
    <form method="post">
      {% csrf_token %} {{ form.as_p }}
      <button type="submit">Submit</button>
    </form>
    <a href="{% url 'home' %}">Back to Home</a>
  </body>
</html>

Step 8: Run the Server

python manage.py runserver

Output:

The homepage displays all registered participants with options to edit or delete.
The registration page allows users to register for the event.
Users can update or delete their registrations.

Post Practical Questions:

Which of the following is the correct sequence of CRUD operations in Django?
- b) Create → Read → Update → Delete
What does the redirect() function do in Django views?
- b) It redirects the user to a specified URL.
How can you set up a database for a Django project?
- Configure the DATABASES setting in settings.py, install necessary database drivers, run python manage.py migrate, and create a superuser if needed.

Conclusion: A Django-based Youth Festival Registration System was developed, enabling users to register, update, and manage their event participation using CRUD operations.

IWSD Lab Manual

On This Page

Practical 01

Practical 02

Practical 03

Practical 04

Practical 05

Practical 06

Practical 07

Practical 08