Django Demo

Installation of Django

where python
set path=
E:
mkdir Django_Demo
cd Django_Demo
python -m venv MYENV
MYENV\Scripts\activate

Once the environment is activated install django.

pip install django
python –m django –-version

IT IS THE TIME TO CREATE YOUR 1st DJANGO PROJECT

django-admin startproject project_Hello
cd project_Hello
python manage.py migrate
python manage.py runserver
Press Ctrl+C to come back to (MYENV) E:\Django_Demo\project_Hello> path.

Inside the project directory, create a new app: Execute the following code

python manage.py startapp hello_app

Then, add hello_app to the INSTALLED_APPS section in settings.py file under the folder project_hello.

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'hello_app'
]

Open views.py file which is placed inside the folder hello_app and add the following code:

from django.shortcuts import render

# Create your views here.
from django.http import HttpResponse

def function_hello_world(request):
    return HttpResponse("Hello, World!")

Open urls.py file which is placed inside the folder hello_app (create urls.py file it if it doesn’t exist) and add the following code:

from django.urls import path

from .views import function_hello_world

urlpatterns = [

    path("", function_hello_world),  # Maps the root URL to the hello_world view

]

Open urls.py file which is placed inside the folder project_hello and add the following code:

from django.contrib import admin
from django.urls import path, include

urlpatterns = [
    path('admin/', admin.site.urls),
    path("",include('hello_app.urls'))
]

RUN THE DJANGO SERVER

python manage.py migrate
python manage.py runserver
Press Ctrl+C to come back to (MYENV) E:\Django_Demo\project_Hello> path.

If you have already created an environment then you have to go to the path of the folder and activate the environment to continue.

cd E:\Django_Demo
E:
MYENV\Scripts\activate
cd project_Hello
python manage.py migrate
python manage.py runserver

Login activity using Django

Activate the environment by going to the path Django_Demo folder in anaconda prompt

MYENV\Scripts\activate

Create a Django project and app for login activity:

django-admin startproject project_login
cd project_login
python manage.py startapp login_app

Add login_app to INSTALLED_APPS section in the file Settings.py placed inside project_login:

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'login_app'
]

Create Login and Logout Views

Open the views.py file placed inside login_app folder and add the following code:

from django.shortcuts import render

# Create your views here.
from django.shortcuts import render, redirect
from django.contrib.auth import authenticate, login, logout
from django.contrib import messages

def login_view(request):
    if request.method == "POST":
        username = request.POST['username']
        password = request.POST['password']
        user = authenticate(request, username=username, password=password)
        if user is not None:
            login(request, user)
            return redirect('dashboard')  # Redirect after login
        else:
            messages.error(request, "Invalid username or password")
    
    return render(request, 'login.html')

def logout_view(request):
    logout(request)
    return redirect('login')

def dashboard_view(request):
    if not request.user.is_authenticated:
        return redirect('login')
    return render(request, 'dashboard.html', {'user': request.user})

Configure URLS

Open the urls.py file placed inside login_app folder and add the following code:

from django.urls import path
from .views import login_view, logout_view, dashboard_view

urlpatterns = [
    path('', login_view, name='login'),
    path('dashboard/', dashboard_view, name='dashboard'),
    path('logout/', logout_view, name='logout'),
]

Open urls.py file placed inside the folder project_login and update the content as shown below:

from django.contrib import admin
from django.urls import path, include

urlpatterns = [
    path('admin/', admin.site.urls),
    path('', include('login_app.urls')),
]

Create a folder named templates inside the login_app folder and create two HTML files namely login.html and dashboard.html

Create Login and Dashboard Templates

<!DOCTYPE html>
<html>
<head>
    <title>Login</title>
</head>
<body>
    <h2>Login</h2>
    {% if messages %}
        {% for message in messages %}
            <p style="color: red;">{{ message }}</p>
        {% endfor %}
    {% endif %}
    <form method="post">
        {% csrf_token %}
        <label>Username:</label>
        <input type="text" name="username" required><br><br>
        <label>Password:</label>
        <input type="password" name="password" required><br><br>
        <button type="submit">Login</button>
    </form>
</body>
</html>

Contents of login.html is as follows:

Content of dashboard.html file is as follows

<!DOCTYPE html>
<html>
<head>
    <title>Dashboard</title>
</head>
<body>
    <h2>Welcome, {{ user.username }}!</h2>
    <a href="{% url 'logout' %}">Logout</a>
</body>
</html>

Create a Superuser (For Testing)

python manage.py migrate
# first migrate and then create super user
python manage.py createsuperuser

Run the Server (Give super username and password as input)

python manage.py runserver

Calculate FD returns and EMI

Step 1: Set Up Django Project

Activate the environment by going to the path Django_Demo folder in anaconda prompt

cd E:\Django_Demo
E:
MYENV\Scripts\activate

Create a Django Project 

django-admin startproject project_bank
cd project_bank

Create a Django Banking App

python manage.py startapp banking_app

Register the App in settings.py in project_bank folder

Then, add bank_app to the INSTALLED_APPS section in settings.py file under the folder project_bank.

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'banking_app'
]

Step 2: Define Data Models

Open banking_app/models.py and define models for Fixed Deposit and Loan.

Open the models.py file placed inside the banking_app and add the following code.

from django.db import models

class FixedDeposit(models.Model):
    principal = models.DecimalField(max_digits=10, decimal_places=2)  # Initial amount
    rate_of_interest = models.FloatField()  # Annual interest rate in percentage
    time_period = models.IntegerField()  # Time period in years
    compounding_frequency = models.IntegerField(default=1)  # Number of times interest is compounded per year

    def calculate_fd_return(self):
        """
        Formula: A = P (1 + r/n)^(nt)
        Where:
        A = Maturity amount
        P = Principal amount
        r = Annual interest rate (in decimal)
        n = Compounding frequency per year
        t = Time period in years
        """
        P = float(self.principal)
        r = float(self.rate_of_interest) / 100  # Convert percentage to decimal
        n = self.compounding_frequency
        t = self.time_period

        A = P * (1 + r / n) ** (n * t)
        return round(A, 2)

    def __str__(self):
        return f"FD - {self.principal} at {self.rate_of_interest}% for {self.time_period} years"


class Loan(models.Model):
    loan_amount = models.DecimalField(max_digits=10, decimal_places=2)  # Principal loan amount
    annual_interest_rate = models.FloatField()  # Annual interest rate in percentage
    tenure_months = models.IntegerField()  # Loan tenure in months

    def calculate_emi(self):
        """
        Formula: EMI = [P * r * (1+r)^n] / [(1+r)^n - 1]
        Where:
        P = Loan amount (principal)
        r = Monthly interest rate (annual rate / 12 / 100)
        n = Number of months
        """
        P = float(self.loan_amount)
        r = (float(self.annual_interest_rate) / 100) / 12  # Convert annual rate to monthly decimal rate
        n = self.tenure_months

        if r == 0:  # If interest rate is 0
            emi = P / n
        else:
            emi = (P * r * (1 + r) ** n) / ((1 + r) ** n - 1)
        
        return round(emi, 2)

    def __str__(self):
        return f"Loan - {self.loan_amount} at {self.annual_interest_rate}% for {self.tenure_months} months"


class Loan(models.Model):
    loan_amount = models.DecimalField(max_digits=10, decimal_places=2)  # Principal loan amount
    annual_interest_rate = models.FloatField()  # Annual interest rate in percentage
    tenure_months = models.IntegerField()  # Loan tenure in months

    def calculate_emi(self):
        """
        Formula: EMI = [P * r * (1+r)^n] / [(1+r)^n - 1]
        Where:
        P = Loan amount (principal)
        r = Monthly interest rate (annual rate / 12 / 100)
        n = Number of months
        """
        P = float(self.loan_amount)
        r = (float(self.annual_interest_rate) / 100) / 12  # Convert annual rate to monthly decimal rate
        n = self.tenure_months

        if r == 0:  # If interest rate is 0
            emi = P / n
        else:
            emi = (P * r * (1 + r) ** n) / ((1 + r) ** n - 1)
        
        return round(emi, 2)

    def __str__(self):
        return f"Loan - {self.loan_amount} at {self.annual_interest_rate}% for {self.tenure_months} months"

Apply Migrations

python manage.py makemigrations banking_app
python manage.py migrate

Step 3: Create Views for Calculation

Open views.py placed inside the banking_app folder and define functions for FD return and EMI calculation.

from django.shortcuts import render
from .models import FixedDeposit, Loan

def fixed_deposit_view(request):
    if request.method == "POST":
        principal = float(request.POST.get("principal"))
        rate_of_interest = float(request.POST.get("rate_of_interest"))
        time_period = int(request.POST.get("time_period"))
        compounding_frequency = int(request.POST.get("compounding_frequency"))

        fd = FixedDeposit(
            principal=principal, rate_of_interest=rate_of_interest,
            time_period=time_period, compounding_frequency=compounding_frequency
        )
        maturity_amount = fd.calculate_fd_return()

        return render(request, "fixed_deposit.html", {"maturity_amount": maturity_amount})

    return render(request, "fixed_deposit.html")


def loan_emi_view(request):
    if request.method == "POST":
        loan_amount = float(request.POST.get("loan_amount"))
        annual_interest_rate = float(request.POST.get("annual_interest_rate"))
        tenure_months = int(request.POST.get("tenure_months"))

        loan = Loan(
            loan_amount=loan_amount, annual_interest_rate=annual_interest_rate, tenure_months=tenure_months
        )
        emi_amount = loan.calculate_emi()

        return render(request, "loan_emi.html", {"emi_amount": emi_amount})

    return render(request, "loan_emi.html")

Step 4: Define URLs

Open urls.py placed inside the folder banking_app and create URL patterns.

from django.urls import path
from .views import fixed_deposit_view, loan_emi_view

urlpatterns = [
    path("fixed-deposit/", fixed_deposit_view, name="fixed_deposit"),
    path("loan-emi/", loan_emi_view, name="loan_emi"),
]

Open urls.py file placed inside the folder project_bank and update the code:

from django.contrib import admin
from django.urls import path, include

urlpatterns = [
    path('admin/', admin.site.urls),
    path("banking_app/", include("banking_app.urls")),
]

Step 5: Create HTML Templates

Create a folder named templates inside the folder banking_app and create two HTML files namely fixed_deposit.html and loan_emi.html

fixed_deposit.html

<form method="post">
    {% csrf_token %}
    Principal: <input type="number" name="principal" step="0.01" required><br>
    Rate of Interest (%): <input type="number" name="rate_of_interest" step="0.01" required><br>
    Time Period (Years): <input type="number" name="time_period" required><br>
    Compounding Frequency: <input type="number" name="compounding_frequency" value="1" required><br>
    <button type="submit">Calculate</button>
</form>

{% if maturity_amount %}
    <p>Maturity Amount: {{ maturity_amount }}</p>
{% endif %}

loan_emi.html



<form method="post">
    {% csrf_token %}
    Loan Amount: <input type="number" name="loan_amount" step="0.01" required><br>
    Annual Interest Rate (%): <input type="number" name="annual_interest_rate" step="0.01" required><br>
    Tenure (Months): <input type="number" name="tenure_months" required><br>
    <button type="submit">Calculate</button>
</form>

{% if emi_amount %}
    <p>Monthly EMI: {{ emi_amount }}</p>
{% endif %}

Step 6: Run the Project

python manage.py runserver

Use the following URLs

http://127.0.0.1:8000/banking_app/fixed-deposit/

http://127.0.0.1:8000/banking_app/loan-emi/