From Complete Beginner to 2D Arrays

Python Basics
Variables & Data Types
Input & Output
Decision Making (if-else)
Loops
Functions
Lists (Arrays)
Records/Dictionaries
While Loops & Menu Systems
Password Validation & Attempt Tracking
Score Calculation & Game Logic
Practical Applications
2D Arrays (Matrices)
Quick Reference Card

Python Basics

What is Python?

Python is a programming language that is easy to read and write. It’s great for beginners!

Your First Program

# This is a comment - Python ignores this
print("Hello, World!")

Output:

Hello, World!

Key Points:

print() is used to display output
Text inside quotes " " is called a string
Comments start with # and are ignored by Python

Variables & Data Types

What are Variables?

Variables are containers for storing data values.

Basic Data Types

# Integer - whole numbers
age = 16
year = 2026

# Float - decimal numbers
price = 99.99
temperature = 36.5

# String - text (in quotes)
name = "Arj"
school = 'ABC School'  # Single quotes also work

# Boolean - True or False
is_student = True
passed_exam = False

print(age)
print(name)
print(is_student)

Variable Naming Rules

Can contain letters, numbers, and underscores
Must start with a letter or underscore
Cannot start with a number
Case-sensitive (Age and age are different)

# Valid variable names
student_name = "Ali"
roll_number = 101
marks1 = 85
_total = 500

# Invalid variable names (will cause error)
# 1st_student = "Ali"    # Cannot start with number
# my-name = "Ali"         # Hyphen not allowed
# class = "10"            # 'class' is a reserved word

Type Conversion

Converting between different data types:

# Converting string to integer
num_str = "123"
num_int = int(num_str)
print(num_int + 10)  # 133

# Converting integer to string
age = 16
age_str = str(age)
print("I am " + age_str + " years old")

# Converting string to float
price_str = "99.99"
price_float = float(price_str)
print(price_float + 10)  # 109.99

# Converting to boolean
print(bool(1))    # True
print(bool(0))    # False
print(bool(""))   # False
print(bool("Hi")) # True

Checking Data Types

x = 10
y = 3.14
z = "Hello"

print(type(x))  # <class 'int'>
print(type(y))  # <class 'float'>
print(type(z))  # <class 'str'>

Input & Output

Taking Input from User

# Taking input (always returns a string)
name = input("Enter your name: ")
print("Hello", name)

# Taking number input (need to convert)
age = int(input("Enter your age: "))
print("Next year you will be", age + 1)

marks = float(input("Enter your marks: "))
print("Your marks are", marks)

Multiple Inputs

# Taking multiple inputs
name = input("Enter name: ")
age = int(input("Enter age: "))
city = input("Enter city: ")

print("Name:", name)
print("Age:", age)
print("City:", city)

Formatted Output

# Simple output
name = "Ali"
marks = 85
print("Student", name, "got", marks, "marks")

# Using + for concatenation (joining strings)
print("Student " + name + " got " + str(marks) + " marks")

Decision Making (if-else)

if Statement

age = 18

if age >= 18:
    print("You are an adult")

if-else Statement

marks = 75

if marks >= 40:
    print("Pass")
else:
    print("Fail")

if-elif-else Statement

marks = 85

if marks >= 90:
    print("Grade A")
elif marks >= 80:
    print("Grade B")
elif marks >= 70:
    print("Grade C")
elif marks >= 60:
    print("Grade D")
else:
    print("Grade F")

Multiple Conditions (and, or)

# and - both conditions must be True
age = 20
has_id = True

if age >= 18 and has_id == True:
    print("You can vote")

# or - at least one condition must be True
day = "Saturday"
if day == "Saturday" or day == "Sunday":
    print("It's a holiday!")

Nested if Statements

num = 15

if num > 0:
    print("Positive number")
    if num % 2 == 0:
        print("Even")
    else:
        print("Odd")
else:
    print("Negative number")

Loops

for Loop

Used when you know how many times to repeat.

# Repeat 5 times
for i in range(5):
    print("Hello", i)

# Output:
# Hello 0
# Hello 1
# Hello 2
# Hello 3
# Hello 4

range() Function

# range(stop) - from 0 to stop-1
for i in range(3):
    print(i)  # 0, 1, 2

# range(start, stop) - from start to stop-1
for i in range(2, 6):
    print(i)  # 2, 3, 4, 5

# range(start, stop, step) - with step value
for i in range(1, 10, 2):
    print(i)  # 1, 3, 5, 7, 9

while Loop

Used when you don’t know how many times to repeat.

# Count from 1 to 5
count = 1
while count <= 5:
    print(count)
    count = count + 1

# Output: 1 2 3 4 5

break Statement

Exit the loop immediately.

# Stop when user enters 0
while True:
    num = int(input("Enter a number (0 to exit): "))
    if num == 0:
        break
    print("You entered:", num)

continue Statement

Skip to the next iteration.

# Print only even numbers
for i in range(1, 11):
    if i % 2 != 0:  # if odd
        continue
    print(i)  # 2, 4, 6, 8, 10

Functions

What are Functions?

Functions are reusable blocks of code that perform a specific task.

Defining and Calling Functions

# Defining a function
def greet():
    print("Hello!")
    print("Welcome to Python")

# Calling the function
greet()
greet()  # Can call multiple times

Functions with Parameters

# Function with one parameter
def greet_person(name):
    print("Hello", name)

greet_person("Ali")
greet_person("Sara")

# Function with multiple parameters
def add_numbers(a, b):
    result = a + b
    print("Sum is", result)

add_numbers(5, 3)
add_numbers(10, 20)

Functions with Return Values

# Function that returns a value
def add(a, b):
    return a + b

result = add(5, 3)
print("Result:", result)  # 8

# Function that returns multiple values
def get_min_max(numbers):
    smallest = min(numbers)
    largest = max(numbers)
    return smallest, largest

nums = [10, 5, 8, 20, 3]
small, large = get_min_max(nums)
print("Smallest:", small)
print("Largest:", large)

Functions with Default Parameters

def greet(name, greeting="Hello"):
    print(greeting, name)

greet("Ali")           # Uses default "Hello"
greet("Sara", "Hi")    # Uses provided "Hi"

Scope of Variables

# Global variable (outside function)
x = 10

def my_function():
    # Local variable (inside function)
    y = 5
    print("Inside function - x:", x)  # Can access global
    print("Inside function - y:", y)  # Can access local

my_function()
print("Outside - x:", x)  # Works
# print("Outside - y:", y)  # Error! y doesn't exist here

Function Examples

# Example 1: Calculate area of rectangle
def area_rectangle(length, width):
    return length * width

area = area_rectangle(5, 3)
print("Area:", area)

# Example 2: Check if number is even
def is_even(num):
    if num % 2 == 0:
        return True
    else:
        return False

print(is_even(4))  # True
print(is_even(7))  # False

# Example 3: Convert temperature
def celsius_to_fahrenheit(celsius):
    fahrenheit = (celsius * 9/5) + 32
    return fahrenheit

temp = celsius_to_fahrenheit(30)
print("30°C =", temp, "°F")

Lists (Arrays)

Creating Lists

# Empty list
empty_list = []

# List with values
numbers = [1, 2, 3, 4, 5]
names = ["Ali", "Sara", "Ahmed"]
mixed = [10, "Hello", 3.14, True]

# Create list with repeated values
zeros = [0] * 5  # [0, 0, 0, 0, 0]

Accessing List Elements

fruits = ["apple", "banana", "orange", "mango"]

# Access by index (starts at 0)
print(fruits[0])  # apple
print(fruits[1])  # banana
print(fruits[3])  # mango

# Negative indexing (from end)
print(fruits[-1])  # mango (last item)
print(fruits[-2])  # orange

# Length of list
print(len(fruits))  # 4

Modifying Lists

fruits = ["apple", "banana", "orange"]

# Change an element
fruits[1] = "grapes"
print(fruits)  # ["apple", "grapes", "orange"]

# Add elements
fruits.append("mango")     # Add at end
fruits.insert(1, "kiwi")   # Add at specific position
print(fruits)

# Remove elements
fruits.remove("apple")     # Remove by value
fruits.pop()               # Remove last element
fruits.pop(1)              # Remove by index
print(fruits)

Looping Through Lists

fruits = ["apple", "banana", "orange"]

# Method 1: Direct iteration
for fruit in fruits:
    print(fruit)

# Method 2: Using index
for i in range(len(fruits)):
    print(fruits[i])

List Operations

numbers = [5, 2, 8, 1, 9]

# Sum of all elements
total = sum(numbers)
print("Sum:", total)

# Minimum and maximum
minimum = min(numbers)
maximum = max(numbers)
print("Min:", minimum, "Max:", maximum)

# Sort list
numbers.sort()
print("Sorted:", numbers)

# Reverse list
numbers.reverse()
print("Reversed:", numbers)

# Check if item exists
if 8 in numbers:
    print("8 is in the list")

List Functions

def calculate_average(marks_list):
    total = sum(marks_list)
    count = len(marks_list)
    return total / count

marks = [75, 80, 90, 65, 85]
avg = calculate_average(marks)
print("Average:", avg)

Records/Dictionaries

What are Dictionaries?

Dictionaries store data in key-value pairs, like a real dictionary where you look up a word (key) to find its meaning (value).

Creating Dictionaries

# Empty dictionary
student = {}

# Dictionary with data
student = {
    "name": "Ali",
    "age": 16,
    "grade": "10th",
    "marks": 85
}

print(student)

Accessing Dictionary Values

student = {
    "name": "Ali",
    "age": 16,
    "city": "Karachi"
}

# Access by key
print(student["name"])     # Ali
print(student["age"])      # 16

# Using get() method (safer - no error if key doesn't exist)
print(student.get("city"))      # Karachi
print(student.get("country"))   # None (doesn't exist)

Modifying Dictionaries

student = {"name": "Ali", "age": 16}

# Add new key-value pair
student["city"] = "Karachi"
print(student)  # {"name": "Ali", "age": 16, "city": "Karachi"}

# Modify existing value
student["age"] = 17
print(student)  # {"name": "Ali", "age": 17, "city": "Karachi"}

# Remove a key-value pair
del student["city"]
print(student)  # {"name": "Ali", "age": 17}

Looping Through Dictionaries

student = {
    "name": "Ali",
    "age": 16,
    "city": "Karachi",
    "grade": "10th"
}

# Loop through keys
for key in student:
    print(key, ":", student[key])

# Loop through key-value pairs
for key, value in student.items():
    print(key, "=", value)

# Get all keys
keys = student.keys()
print(keys)

# Get all values
values = student.values()
print(values)

List of Dictionaries (Records)

# Multiple student records
students = [
    {"name": "Ali", "age": 16, "marks": 85},
    {"name": "Sara", "age": 15, "marks": 92},
    {"name": "Ahmed", "age": 17, "marks": 78}
]

# Access each student's data
for student in students:
    print(student["name"], "got", student["marks"], "marks")

# Find student with highest marks
highest = students[0]
for student in students:
    if student["marks"] > highest["marks"]:
        highest = student

print("Top student:", highest["name"], "with", highest["marks"], "marks")

Dictionary Functions

def add_student(students_list, name, age, marks):
    student = {
        "name": name,
        "age": age,
        "marks": marks
    }
    students_list.append(student)
    return students_list

def get_average_marks(students_list):
    total = 0
    for student in students_list:
        total = total + student["marks"]
    return total / len(students_list)

# Using the functions
my_students = []
my_students = add_student(my_students, "Ali", 16, 85)
my_students = add_student(my_students, "Sara", 15, 92)

avg = get_average_marks(my_students)
print("Average marks:", avg)

Student Record System Example

def display_menu():
    print("\n--- Student Record System ---")
    print("1. Add Student")
    print("2. Display All Students")
    print("3. Search Student")
    print("4. Calculate Class Average")
    print("5. Exit")

def add_student(students):
    name = input("Enter student name: ")
    age = int(input("Enter age: "))
    marks = float(input("Enter marks: "))

    student = {
        "name": name,
        "age": age,
        "marks": marks
    }
    students.append(student)
    print("Student added successfully!")

def display_all(students):
    if len(students) == 0:
        print("No students in record")
    else:
        print("\nAll Students:")
        for i in range(len(students)):
            s = students[i]
            print(i+1, "-", s["name"], ", Age:", s["age"], ", Marks:", s["marks"])

def search_student(students):
    name = input("Enter name to search: ")
    found = False
    for student in students:
        if student["name"].lower() == name.lower():
            print("Found:", student["name"], ", Age:", student["age"], ", Marks:", student["marks"])
            found = True
    if not found:
        print("Student not found")

def calculate_average(students):
    if len(students) == 0:
        print("No students to calculate average")
    else:
        total = 0
        for student in students:
            total = total + student["marks"]
        avg = total / len(students)
        print("Class average:", avg)

# Main program
students = []
choice = 0

while choice != 5:
    display_menu()
    choice = int(input("Enter your choice: "))

    if choice == 1:
        add_student(students)
    elif choice == 2:
        display_all(students)
    elif choice == 3:
        search_student(students)
    elif choice == 4:
        calculate_average(students)
    elif choice == 5:
        print("Goodbye!")
    else:
        print("Invalid choice!")

While Loops & Menu Systems

Simple Menu System

A basic menu that continues until the user chooses to exit.

# Simple Menu System
def Display():
    userInput = 0
    while userInput != 3:
        userInput = int(input("Enter a number: 1 for Hello, 2 for Goodbye and 3 for exit "))
        if userInput == 1:
            print("Hello")
        elif userInput == 2:
            print("Goodbye")

Display()

Key Points:

While loop runs until condition becomes False
User input controls which option runs
Program ends when user enters 3

Password Validation & Attempt Tracking

Password Retry System

Allow limited attempts for password entry.

def password():
    passwordS = "CS123"
    tries = 3
    access = False

    while tries > 0 and not access:
        password = input("Enter your password: ")

        if password == passwordS:
            print("Access granted")
            access = True
        else:
            tries -= 1
            print("Try Again.", tries, "left")

    if not access:
        print("Access denied")

password()

Key Points:

Counter variable tries tracks remaining attempts
Boolean flag access tracks if login successful
Loop stops when either condition becomes False

Score Calculation & Game Logic

Game Score Tracker

Process scores with special rules.

def scoreCalculator():
    sumAll = 0
    for i in range(5):
        scores = int(input("Enter your game score: "))
        if scores < 0:
            print("Invalid score.")
        elif scores <= 50 and scores > 0:
            sumAll += scores
        elif scores > 50:
            sumAll = sumAll + scores * 2

    if sumAll > 200:
        print("high score")
    else:
        print("try again")

scoreCalculator()

Key Points:

For loop for fixed number of rounds
Multiple conditions with if-elif
Cumulative sum with += operator

Practical Applications

Coffee Shop Order Calculator

def Calcprices():
    print("Coffee Prices:")
    print("Small = Rs 100")
    print("Medium = Rs 150")
    print("Large = Rs 250")
    print("Adding Cream = Rs 20")

Calcprices()

price = 0
total = 0
choice = ""

while choice != "done":
    choice = input("Do you want S/M/L (enter done to exit): ").lower()
    if choice == "done":
        break
    elif choice == "small":
        total += 100
    elif choice == "medium":
        total += 150
    elif choice == "large":
        total += 250

cream = input("Do you want cream with your coffee (Y/N): ").lower()
if cream == "yes":
    total += 20

print("your total is", total)

Parking Fee Calculator

def displayboard():
    print("Parking Charges:")
    print("0-1 hours = Rs 20")
    print("1-3 hours = Rs 50")
    print("5 hours = Rs 100 with extra Rs 20")

displayboard()

charges = 0
total = 0
exit = False

while exit != True:
    hours = float(input("Enter the hours spent parking (enter 0 to exit): "))
    if hours == 0:
        exit = True
        print("You have exited.")
    elif hours > 0 and hours <= 1:
        charges = 20
    elif hours > 1 and hours <= 3:
        charges = 50
    elif hours > 3 and hours <= 5:
        charges = 100
    else:
        charges = 120

    total += charges

print("Your parking charges are", total)

Student Marks Analyzer

marks = []
grades = []
sum = 0
count = 0
Acount, Bcount, Ccount, Dcount, Fcount = 0, 0, 0, 0, 0

userInput = 0
while userInput != -1:
    userInput = int(input("Enter student marks: "))
    if userInput == -1:
        break
    else:
        marks.append(userInput)
        sum = sum + userInput
        count = count + 1
        if userInput >= 90:
            grades.append('A')
            Acount = Acount + 1
        elif userInput >= 80:
            grades.append('B')
            Bcount = Bcount + 1
        elif userInput >= 70:
            grades.append('C')
            Ccount = Ccount + 1
        elif userInput >= 60:
            grades.append('D')
            Dcount = Dcount + 1
        else:
            grades.append('F')
            Fcount = Fcount + 1

print("The average score is", sum / count)
print("Number of A's are", Acount)
print("Number of B's are", Bcount)
print("Number of C's are", Ccount)
print("Number of D's are", Dcount)
print("Number of F's are", Fcount)

print(marks)
print(grades)

Employee Salary Calculator

def display():
    print("first 40 hours: Rs 500")
    print("next 10 hours(41-50): Rs 600")
    print("above 50 hours: Rs 700")

display()

highest = -999999
lowest = 999999
count = 0
pay = 0
total = 0
salarylist = []
hourslist = []
exit = False

while exit != True:
    hours = float(input("Enter Employees' hours worked: "))
    if hours == 0:
        exit = True
    elif hours <= 40:
        count = count + 1
        pay = 500
        cost = pay * hours
        salarylist.append(cost)
        hourslist.append(hours)
    elif hours >= 41 and hours <= 50:
        count = count + 1
        pay = 600
        cost = pay * hours
        salarylist.append(cost)
        hourslist.append(hours)
    else:
        count = count + 1
        pay = 700
        cost = pay * hours
        salarylist.append(cost)
        hourslist.append(hours)

    total = total + pay * hours
    average = total / count
    if cost > highest:
        highest = cost
    if cost < lowest:
        lowest = cost

print("Hours List For Employees:")
print("[", end=" ")
for p in hourslist:
    print(p, end=" ")
print("]")

print("Salary List For Employees:")
print("[", end=" ")
for x in salarylist:
    print(x, end=" ")
print("]")

print("The total amount of salary given is", total)
print("The highest salary given is", highest)
print("The lowest salary given is", lowest)
print("The average salary given is", average)

Hotel Room Booking System

def extraRooms():
    extra = input("Do you have extra people? ")
    if extra == "yes":
        return True
    else:
        return False

def amountOfNights():
    nights = int(input("Enter the number of nights: "))
    return nights

print("Single (1 person): Rs. 2000/night")
print("Double (2 people): Rs. 3000/night")
print("Family (4 people): Rs. 5000/night")
print("Extra person: +Rs. 500")
print()

priceslist = []
price = 0
totalCost = 0
exit = True
totalNights = 0
sCount, dCount, fCount = 0, 0, 0

while exit != False:
    roomtype = input("(single/double/family) for extra (+500) and enter 'stop' to leave: ")
    if roomtype == "stop":
        exit = False
    elif roomtype == "single":
        price = 2000
        extra = extraRooms()
        if extra == True:
            price = price + 500
        nights = amountOfNights()
        price = price * nights
        priceslist.append(price)
        totalCost = totalCost + price
        sCount = sCount + 1
        totalNights = totalNights + nights
    elif roomtype == "double":
        price = 3000
        extra = extraRooms()
        if extra == True:
            price = price + 500
        nights = amountOfNights()
        price = price * nights
        priceslist.append(price)
        totalCost = totalCost + price
        dCount = dCount + 1
        totalNights = totalNights + nights
    elif roomtype == "family":
        price = 5000
        extra = extraRooms()
        if extra == True:
            price = price + 500
        nights = amountOfNights()
        price = price * nights
        priceslist.append(price)
        totalCost = totalCost + price
        fCount = fCount + 1
        totalNights = totalNights + nights
    else:
        print("invalid room type, Enter Again.")

print(priceslist)
print("The total Cost of all rooms is:", totalCost)

if sCount > dCount and sCount > fCount:
    print("Most Booked Room is Single Room")
elif dCount > sCount and dCount > fCount:
    print("Most Booked Room is Double Room")
elif fCount > sCount and fCount > dCount:
    print("Most Booked Room is Family Room")
else:
    print("All Rooms had the same amount of bookings")

TotalCount = sCount + dCount + fCount
print("The average stay duration is:", totalNights / TotalCount)

2D Arrays (Matrices)

Creating 2D Arrays

# Method 1: Direct initialization
Matrix = [
    [1, 2, 3],
    [4, 5, 6],
    [7, 8, 9]
]

# Method 2: Using list comprehension
Data = [[0] * 3 for _ in range(3)]
print(Data)

# Method 3: Taking user input
rows = int(input("enter the number of rows: "))
cols = int(input("enter the number of columns: "))

matrix = [[0] * cols for i in range(rows)]

for i in range(rows):
    for j in range(cols):
        matrix[i][j] = int(input("Enter value: "))

# Displaying a 2D array
for i in range(rows):
    print("[", end=" ")
    for j in range(cols):
        print(matrix[i][j], end=" ")
    print("]")

Row & Column Sum

Data = [[0] * 3 for i in range(3)]

# Inputting data
for rows in range(3):
    for cols in range(3):
        Data[rows][cols] = int(input("Enter a number: "))

# Calculating row and column sums
for rows in range(3):
    rowSum = 0
    colSum = 0
    for cols in range(3):
        rowSum = rowSum + Data[rows][cols]
        colSum = colSum + Data[cols][rows]
    print("The sum of row", rows, "is", rowSum)
    print("The sum of col", rows, "is", colSum)

Search Element

data = [
    [1, 2, 3],
    [4, 5, 6],
    [7, 8, 9]
]

num = int(input("enter a number: "))
found = False

for i in range(3):
    for j in range(3):
        if data[i][j] == num:
            found = True

if found:
    print("The number you entered is in the list")
else:
    print("The number you entered is not in the list")

Matrix Transpose

rows = int(input("enter the number of rows: "))
cols = int(input("enter the number of columns: "))

data = [[0] * cols for i in range(rows)]

for i in range(rows):
    for j in range(cols):
        data[i][j] = int(input("Enter the value: "))

print("Original Matrix:")
for i in range(rows):
    print("[", end=" ")
    for j in range(cols):
        print(data[i][j], end=" ")
    print("]")

newData = [[0] * rows for i in range(cols)]

for i in range(cols):
    for j in range(rows):
        newData[i][j] = data[j][i]

print("Transpose Matrix:")
for i in range(cols):
    print("[", end=" ")
    for j in range(rows):
        print(newData[i][j], end=" ")
    print("]")

Find Maximum Value

rows = int(input("enter the number of rows: "))
cols = int(input("enter the number of columns: "))

D_list = [[0] * cols for i in range(rows)]

for i in range(rows):
    for j in range(cols):
        D_list[i][j] = int(input("enter number: "))

# Display matrix
for i in range(rows):
    print("[", end=" ")
    for j in range(cols):
        print(D_list[i][j], end=" ")
    print("]")

# Find maximum
max = D_list[0][0]
for i in range(rows):
    for j in range(cols):
        if D_list[i][j] > max:
            max = D_list[i][j]

print("The maximum value is: ", max)

Diagonal Sum

rows = int(input("Enter number of rows: "))
cols = int(input("Enter number of columns: "))

data = [[0] * cols for i in range(rows)]

for i in range(rows):
    for j in range(cols):
        data[i][j] = int(input("Enter a number: "))

# Calculating diagonal sums
dSum = 0
aSum = 0

for i in range(rows):
    dSum = dSum + data[i][i]
    aSum = aSum + data[rows - 1 - i][i]

print("The diagonal sum is ", dSum)
print("The anti diagonal sum is ", aSum)

Matrix Addition

rows = int(input("Enter number of rows: "))
cols = int(input("Enter number of columns: "))

A = [[0] * cols for i in range(rows)]
B = [[0] * cols for i in range(rows)]

print("Enter the values of A:")
for i in range(rows):
    for j in range(cols):
        A[i][j] = int(input("Enter the value: "))

print("Enter the values of B:")
for i in range(rows):
    for j in range(cols):
        B[i][j] = int(input("Enter the value: "))

C = [[0] * cols for i in range(rows)]

for i in range(rows):
    for j in range(cols):
        C[i][j] = A[i][j] + B[i][j]

print("The result of Matrix addition of A and B is:")
for i in range(rows):
    print("[", end=" ")
    for j in range(cols):
        print(C[i][j], end=" ")
    print("]")

Student Marks Analysis System

def averagemarks(total, count):
    return total / count

total = 0
count = 3
rows = 5
cols = 3
highest = 0

D_list = [[0] * cols for i in range(rows)]

for r in range(rows):
    total = 0
    for c in range(cols):
        marks = int(input("Enter your marks: "))
        D_list[r][c] = marks
        total = total + marks
    avg = averagemarks(total, 3)

    if avg < 50:
        print("Fail")
    else:
        print("Pass")

    if avg > highest:
        highest = avg

print("The highest average marks is: ", highest)

Classroom Attendance System

def countattendance(student_record):
    total = 0
    for i in student_record:
        total = total + i
    return total

students = 4
days = 5
attendance = []

for i in range(students):
    student_record = []
    for j in range(days):
        present = int(input("Mark attendance. 1 for present and 0 for absent: "))
        student_record.append(present)
    attendance.append(student_record)
    total = countattendance(student_record)
    if total < 3:
        print("Low attendance")
    print("Total attendance for student", i, ": ", total)

print("Attendance Data (Student x Days)")
print("M T W T F")
for i in range(students):
    for j in range(days):
        print(attendance[i][j], end=" ")
    print()

Cinema Seat Booking System

def bookseat(seatstatus):
    print("total 30 seats")
    print("Seat availability")
    print("0 = Available, 1 = Booked")
    r = int(input("Enter the row you want to book (0-4): "))
    c = int(input("Enter the column you want to book (0-5): "))

    if seatstatus[r][c] == 0:
        seatstatus[r][c] = 1
        print("Booking Successful")
    else:
        print("The seat is already booked. Please choose another one")

    return seatstatus

def display(seatstatus):
    print("Available seats")
    print("0 = Available, 1 = Booked")
    for i in range(5):
        print("[", end=" ")
        for j in range(6):
            print(seatstatus[i][j], end=" ")
        print("]")

rows = 5
seats = 6
seatstatus = [[0] * seats for i in range(rows)]

userInput = ""
while userInput != "stop":
    display(seatstatus)
    seatstatus = bookseat(seatstatus)
    userInput = input("Do you want to make more bookings? type 'stop' to exit: ")

Quick Reference Card

Concept	Syntax	Example
Print	`print()`	`print("Hello")`
Input	`input()`	`name = input("Name: ")`
Variable	`name = value`	`age = 16`
If statement	`if condition:`	`if age >= 18:`
If-else	`if: ... else:`	`if x>0: print("+") else: print("-")`
For loop	`for i in range(n):`	`for i in range(5):`
While loop	`while condition:`	`while x < 10:`
Function	`def name():`	`def greet():`
Function with params	`def name(p1, p2):`	`def add(a, b):`
Return value	`return value`	`return total`
List creation	`list = []`	`marks = [85, 90, 78]`
List append	`list.append(item)`	`marks.append(95)`
Dictionary	`dict = {key:value}`	`student = {"name": "Ali"}`
Access dict	`dict[key]`	`student["name"]`
2D list	`[[0]*cols for _ in range(rows)]`	`matrix = [[0]*3 for _ in range(3)]`
Type conversion	`int()`, `float()`, `str()`	`age = int(input())`
Length	`len()`	`len(list)`
Sum	`sum()`	`total = sum(marks)`

Note: Practice each concept by writing your own programs. Start with simple examples and gradually build more complex programs. Happy coding! 🐍

From Complete Beginner to 2D Arrays

Table of Contents

Python Basics

What is Python?

Your First Program

Variables & Data Types

What are Variables?

Basic Data Types

Variable Naming Rules

Type Conversion

Checking Data Types

Input & Output

Taking Input from User

Multiple Inputs

Formatted Output

Decision Making (if-else)

if Statement

if-else Statement

if-elif-else Statement

Multiple Conditions (and, or)

Nested if Statements

Loops

for Loop

range() Function

while Loop

break Statement

continue Statement

Functions

What are Functions?

Defining and Calling Functions

Functions with Parameters

Functions with Return Values

Functions with Default Parameters

Scope of Variables

Function Examples

Lists (Arrays)

Creating Lists

Accessing List Elements

Modifying Lists

Looping Through Lists

List Operations

List Functions

Records/Dictionaries

What are Dictionaries?

Creating Dictionaries

Accessing Dictionary Values

Modifying Dictionaries

Looping Through Dictionaries

List of Dictionaries (Records)

Dictionary Functions

Student Record System Example

While Loops & Menu Systems

Simple Menu System

Password Validation & Attempt Tracking

Password Retry System

Score Calculation & Game Logic

Game Score Tracker

Practical Applications

Coffee Shop Order Calculator

Parking Fee Calculator

Student Marks Analyzer

Employee Salary Calculator

Hotel Room Booking System

2D Arrays (Matrices)

Creating 2D Arrays

Row & Column Sum

Search Element

Matrix Transpose

Find Maximum Value

Diagonal Sum

Matrix Addition

Student Marks Analysis System

Classroom Attendance System

Cinema Seat Booking System

Quick Reference Card