Python Notes Solutions

Homework Solutions

Homework 1: Variables and Data Types

1. Declare and Print Variables:

# Declare variables
x = 5  # int
y = 3.14  # float
name = "John"  # str
is_admin = True  # bool
colors = ["red", "green", "blue"]  # list

# Print variables
print("x =", x)
print("y =", y)
print("name =", name)
print("is_admin =", is_admin)
print("colors =", colors)

2. Basic Operations:

# Basic arithmetic operations
a = 5
b = 2

print("a + b =", a + b)
print("a - b =", a - b)
print("a * b =", a * b)
print("a / b =", a / b)

3. String Manipulation :

# String manipulation
s = " Hello, World! "

print("Original string:", s)
print("Upper case:", s.upper())
print("Lower case:", s.lower())
print("Strip whitespace:", s.strip())

Homework 2: Control Structures

1. If-Else Statements:

# If-else statement
num = 10

if num % 2 == 0:
    print("The number is even.")
else:
    print("The number is odd.")

For Loops:

# For loop
numbers = [1, 2, 3, 4, 5]

for num in numbers:
    print("Square of", num, "is", num ** 2)

While Loops:

# While loop
i = 1

while i <= 10:
    print(i)
    i += 1

Homework 3: Functions and Modules

1. Simple Function:

# Simple function
def greet(name):
    return "Hello, " + name + "!"
print(greet("John"))  # Output: Hello, John!

Function with Arguments:

# Function with arguments
def add(a, b):
    return a + b

print(add(2, 3))  # Output: 5

Importing Modules:

# Importing modules
import math

angle = 45

print("Sine of", angle, "degrees is", math.sin(math.radians(angle)))
print("Cosine of", angle, "degrees is", math.cos(math.radians(angle)))

Homework 4: Lists and Tuples

1. List Operations:

# List operations
fruits = ["apple", "banana", "cherry"]

print("Original list:", fruits)
print("Index 0:", fruits[0])
print("Slice 1:2:", fruits[1:2])
fruits.append("orange")
print("After append:", fruits)
fruits.extend(["grape", "kiwi"])
print("After extend:", fruits)

Tuple Operations:

# Tuple operations
colors = ("red", "green", "blue")

print("Original tuple:", colors)
print("Index 0:", colors[0])
print("Slice 1:2:", colors[1:2])

List Comprehension:

# List comprehension
numbers = [1, 2, 3, 4, 5]
squares = [num ** 2 for num in numbers]

print("Original list:", numbers)
print("Squares:", squares)

Project Solutions

Project 1: Calculator Program

# Calculator program

def add(a, b):
    return a + b

def sub(a, b):
    return a - b

def mul(a, b):
    return a * b

def div(a, b):
    if b == 0:
        return "Error: Division by zero!"
    return a / b

print("Simple Calculator")
print("1. Addition")
print("2. Subtraction")
print("3. Multiplication")
print("4. Division")

choice = int(input("Enter your choice (1-4): "))
num1 = float(input("Enter first number: "))
num2 = float(input("Enter second number: "))

if choice == 1:
    result = add(num1, num2)
elif choice == 2:
    result = sub(num1, num2)
elif choice == 3:
    result = mul(num1, num2)
elif choice == 4:
    result = div(num1, num2)
else:
    result = "Error: Invalid choice!"

print("Result:", result)

Project 2: To-Do List App

# To-Do List App

tasks = []

def add_task(task):
    tasks.append(task)

def remove_task(task):
    if task in tasks:
        tasks.remove(task)
    else:
        print("Task not found!")

def mark_completed(task):
    if task in tasks:
        tasks[tasks.index(task)] += " (Completed)"
    else:
        print("Task not found!")

while True:
    print("To-Do List App")
    print("1. Add task")
    print("2. Remove task")
    print("3. Mark task as completed")
    print("4. Quit")

    choice = int(input("Enter your choice (1-4): "))

    if choice == 1:
        task = input("Enter task: ")
        add_task(task)
    elif choice == 2:
        task = input("Enter task to remove: ")
        remove_task(task)
    elif choice == 3:
        task = input("Enter task to mark as completed: ")
        mark_completed(task)
    elif choice == 4:
        break
    else:
        print("Error: Invalid choice!")

    print("Tasks:", tasks)

Project 3: Rock, Paper, Scissors Game

# Rock, Paper, Scissors Game

import random

def play_game():
    choices = ["rock", "paper", "scissors"]
    computer_choice = random.choice(choices)

    user_choice = input("Enter your choice (rock, paper, scissors): ")

    if user_choice not in choices:
        print("Error: Invalid choice!")
        return

    print("Computer chose:", computer_choice)

    if user_choice == computer_choice:
        print("It's a tie!")
    elif (user_choice == "rock" and computer_choice == "scissors") or \
         (user_choice == "paper" and computer_choice == "rock") or \
         (user_choice == "scissors" and computer_choice == "paper"):
        print("You win!")
    else:
        print("Computer wins!")

play_game()