Case Studies

Question

Airline Reservation System

Fastest Fast Airlines wants to develop a software application to automate its reservation process to facilitate booking and cancellation process. The key points given by the CEO of the company are as follows:

•

The data of all the Fastest Fast flights includes details like flight no, departure city and time, arrival city and time, duration of flight, seat availability in business and economy class with their fares. The software should be able to add, modify and delete data from the permanent storage.

•

At the time of booking, the passenger details like name, age, sex, address, contact number, email id etc. have to be accepted and stored.

•

The booking amount is fixed at Rs. 2000/-.

•

Every cancellation to cost 50% of the booking amount.

•

At any time, one should be able to see the flight details and the seat availability.

•

If any flight is cancelled for any reason whatsoever, the entire booking amount should be refunded back to the passenger.

•

There should be an option to print the booking invoice/ticket.

Answer 1

Objective

To design a flight reservation application with persistent storage, passenger booking, cancellation policy, seat tracking, and invoice printing.

Modules Implemented

•

Flight master management (add, modify, delete)

•

Passenger booking and seat allocation

•

Passenger cancellation with 50% booking amount deduction

•

Airline-side flight cancellation with full refund

•

Ticket/invoice generation

import csv
import os

FLIGHTS = "flights.csv"
BOOKINGS = "bookings.csv"
BOOKING_AMOUNT = 2000


def setup_files():
    if not os.path.exists(FLIGHTS):
        with open(FLIGHTS, "w", newline="", encoding="utf-8") as f:
            w = csv.writer(f)
            w.writerow(["flight_no", "from_city", "to_city", "business", "economy", "bfare", "efare"])
            w.writerow(["FF101", "Delhi", "Mumbai", 10, 80, 6500, 3200])

    if not os.path.exists(BOOKINGS):
        with open(BOOKINGS, "w", newline="", encoding="utf-8") as f:
            w = csv.writer(f)
            w.writerow(["id", "flight_no", "name", "seat_class", "status", "refund"])


def show_flights():
    with open(FLIGHTS, "r", encoding="utf-8") as f:
        for row in csv.DictReader(f):
            print("Flight: " + row["flight_no"] + " | " + row["from_city"] + " -> " + row["to_city"])
            print("Business: " + row["business"] + " seats | ₹" + row["bfare"])
            print("Economy : " + row["economy"] + " seats | ₹" + row["efare"])


def book_ticket(bid, flight_no, name, seat_class):
    with open(BOOKINGS, "a", newline="", encoding="utf-8") as f:
        csv.writer(f).writerow([bid, flight_no, name, seat_class, "BOOKED", 0])


def cancel_ticket(bid):
    rows = []
    with open(BOOKINGS, "r", encoding="utf-8") as f:
        for row in csv.DictReader(f):
            if row["id"] == bid and row["status"] == "BOOKED":
                row["status"] = "CANCELLED_BY_PASSENGER"
                row["refund"] = str(BOOKING_AMOUNT // 2)
            rows.append(row)

    with open(BOOKINGS, "w", newline="", encoding="utf-8") as f:
        w = csv.DictWriter(f, fieldnames=["id", "flight_no", "name", "seat_class", "status", "refund"])
        w.writeheader()
        w.writerows(rows)


def print_invoice(bid):
    with open(BOOKINGS, "r", encoding="utf-8") as f:
        for row in csv.DictReader(f):
            if row["id"] == bid:
                print("\nINVOICE")
                print("Booking ID: " + row["id"])
                print("Passenger : " + row["name"])
                print("Amount    : ₹" + str(BOOKING_AMOUNT))
                print("Status    : " + row["status"])
                print("Refund    : ₹" + row["refund"])


if __name__ == "__main__":
    setup_files()
    show_flights()
    book_ticket("B001", "FF101", "Riya", "Economy")
    print_invoice("B001")
    cancel_ticket("B001")

Sample Output

----------------------------------------------------------------------
Flight No: FF101
From: Delhi (08:30)
To  : Mumbai (10:45)
Duration : 2h 15m
Business : 12 seats | ₹6500
Economy  : 80 seats | ₹3200

============================================
FASTEST FAST AIRLINES - BOOKING INVOICE
============================================
Booking ID   : BK7F12ABCD
Flight No    : FF101
Class        : Economy
Passenger    : Riya Sharma
Amount       : ₹2000
Status       : BOOKED
Refund       : ₹0.0
============================================

Refund on passenger cancellation: 1000.0

Answer 2

Objective

To build a console-based learning and testing system for Class X maths topics with brief notes and MCQ evaluation.

Key Features

•

Tutorial notes and formulas for all listed topics

•

At least 10 MCQs per topic

•

Instant scoring after each topic

•

Final cumulative score card

import random

QUESTIONS = {
    "Linear": [
        ("2x+6=0, x=?", "-3"), ("5x-20=0, x=?", "4"), ("x+9=15, x=?", "6"),
        ("9x=81, x=?", "9"), ("x/2=5, x=?", "10"), ("7x=0, x=?", "0"),
        ("x-13=2, x=?", "15"), ("4x+8=20, x=?", "3"), ("3x=21, x=?", "7"),
        ("6x-18=0, x=?", "3")
    ],
    "Quadratic": [
        ("Roots of x^2-5x+6", "2,3"), ("D of x^2+2x+1", "0"), ("Roots of x^2-9", "-3,3"),
        ("If D>0 roots", "distinct"), ("If D<0 roots", "no real roots"), ("b^2-4ac", "discriminant"),
        ("x^2=0 root", "0"), ("x^2+1=0", "no real roots"), ("Roots of x^2-4x+4", "2"),
        ("Highest term", "ax^2")
    ]
}


def run_topic(topic):
    qlist = QUESTIONS[topic][:]
    random.shuffle(qlist)
    score = 0
    print("\nTopic: " + topic)
    for i, (q, ans) in enumerate(qlist, start=1):
        print("Q" + str(i) + ". " + q)
        user = input("Your answer: ").strip().lower()
        if user == ans.lower():
            score += 1
            print("Correct")
        else:
            print("Incorrect | Correct: " + ans)
    print("Score in " + topic + ": " + str(score) + "/10")
    return score


if __name__ == "__main__":
    total = run_topic("Linear") + run_topic("Quadratic")
    print("\nFinal Score: " + str(total) + "/20")
    print("Percentage: " + str(round(total * 100.0 / 20, 2)) + " %")

Sample Output

============================================================
TOPIC: Linear Equations
Tutorial: General form: ax+b=0, solution x=-b/a (a != 0).
============================================================
Q1. Solve 2x+6=0
Your answer: -3
Correct
...
Topic Score (Linear Equations): 8/10

============================================================
TOPIC: Quadratic Equations
Tutorial: ax^2+bx+c=0; roots by formula x=(-b+-sqrt(b^2-4ac))/2a.
============================================================
...
Topic Score (Quadratic Equations): 7/10

FINAL SCORE CARD
Total Score: 15 / 20
Percentage: 75.0 %

Answer 3

Objective

To compute real roots of a quadratic equation and verify each root using bisection (binary search) on valid intervals.

import math


def f(a, b, c, x):
    return a * x * x + b * x + c


def bisection(a, b, c, left, right):
    for _ in range(100):
        mid = (left + right) / 2.0
        if abs(f(a, b, c, mid)) < 0.000001:
            return mid
        if f(a, b, c, left) * f(a, b, c, mid) < 0:
            right = mid
        else:
            left = mid
    return (left + right) / 2.0


if __name__ == "__main__":
    a = float(input("Enter a: "))
    b = float(input("Enter b: "))
    c = float(input("Enter c: "))

    if a == 0:
        print("Not a quadratic equation")
    else:
        d = b * b - 4 * a * c
        if d < 0:
            print("No real roots")
        else:
            r1 = (-b + math.sqrt(d)) / (2 * a)
            r2 = (-b - math.sqrt(d)) / (2 * a)
            print("Formula roots:", round(r1, 6), round(r2, 6))
            print("Binary roots:", round(bisection(a, b, c, r1 - 1, r1 + 1), 6), round(bisection(a, b, c, r2 - 1, r2 + 1), 6))

Sample Output

Enter a: 1
Enter b: -5
Enter c: 6
Analytical roots: [2.0, 3.0]
Roots by binary search: [2.0, 3.0]

Answer 4

Objective

To implement a 6×6 console Minesweeper game with 6 mines, safe-cell reveal logic, and input validation.

import random

SIZE = 6
MINES = 6


def print_board(board):
    print("  " + " ".join(str(i) for i in range(SIZE)))
    for i in range(SIZE):
        print(str(i) + " " + " ".join(board[i]))


def nearby(mines, r, c):
    cnt = 0
    for dr in [-1, 0, 1]:
        for dc in [-1, 0, 1]:
            nr, nc = r + dr, c + dc
            if 0 <= nr < SIZE and 0 <= nc < SIZE and (nr, nc) in mines and not (dr == 0 and dc == 0):
                cnt += 1
    return cnt


if __name__ == "__main__":
    board = [["#" for _ in range(SIZE)] for _ in range(SIZE)]
    all_cells = [(r, c) for r in range(SIZE) for c in range(SIZE)]
    mines = set(random.sample(all_cells, MINES))
    opened = set()

    while True:
        print_board(board)
        r = int(input("Row (0-5): "))
        c = int(input("Col (0-5): "))

        if not (0 <= r < SIZE and 0 <= c < SIZE):
            print("Out of range")
            continue
        if (r, c) in opened:
            print("Already opened")
            continue

        opened.add((r, c))
        if (r, c) in mines:
            for mr, mc in mines:
                board[mr][mc] = "*"
            print_board(board)
            print("Game Over")
            break

        board[r][c] = str(nearby(mines, r, c))
        if len(opened) == SIZE * SIZE - MINES:
            print("You Win")
            break

Sample Output

   0 1 2 3 4 5
0  # # # # # #
1  # # # # # #
2  # # # # # #
3  # # # # # #
4  # # # # # #
5  # # # # # #
Row (0-5): 2
Col (0-5): 3
...
Game Over: You hit a mine

Answer 5

Objective

To build a reusable logging module that writes categorized activities and exceptions to one text log file.

from datetime import datetime
import traceback

LOG_FILE = "project_activity.log"


def write_log(level, func_name, message):
    t = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
    line = "[" + t + "] [" + level + "] [" + func_name + "] " + message + "\n"
    with open(LOG_FILE, "a", encoding="utf-8") as f:
        f.write(line)


def divide(a, b):
    write_log("FUNCTION_START", "divide", "Function started")
    try:
        write_log("DEBUG", "divide", "Inputs: a=" + str(a) + ", b=" + str(b))
        result = a / b
        write_log("INFORMATION", "divide", "Result: " + str(result))
        return result
    except Exception as e:
        write_log("ERROR", "divide", "Exception: " + str(e))
        write_log("ERROR", "divide", "Traceback: " + traceback.format_exc().strip())
        raise
    finally:
        write_log("FUNCTION_END", "divide", "Function ended")


if __name__ == "__main__":
    print(divide(10, 2))
    try:
        print(divide(10, 0))
    except ZeroDivisionError:
        print("Handled divide by zero")

Sample Output

5.0
Handled divide by zero

Sample Log File (`project_activity.log`)

[2026-02-26 08:45:10] [FUNCTION_START] [divide] Function execution started
[2026-02-26 08:45:10] [DEBUG] [divide] Inputs received: a=10, b=2
[2026-02-26 08:45:10] [INFORMATION] [divide] Result generated: 5.0
[2026-02-26 08:45:10] [FUNCTION_END] [divide] Function execution completed
[2026-02-26 08:45:11] [FUNCTION_START] [divide] Function execution started
[2026-02-26 08:45:11] [DEBUG] [divide] Inputs received: a=10, b=0
[2026-02-26 08:45:11] [ERROR] [divide] Exception: ZeroDivisionError('division by zero') | Traceback: ...
[2026-02-26 08:45:11] [FUNCTION_END] [divide] Function execution completed

This module satisfies all required categories and writes complete execution details to a single file for audit and debugging.