Python Programming (1323203) - Winter 2023 Solution

# Program to convert Celsius to Fahrenheit

# Get the Celsius temperature from user
celsius = float(input("Enter temperature in Celsius: "))

# Convert to Fahrenheit using the formula: F = (C * 9/5) + 32
fahrenheit = (celsius * 9/5) + 32

# Display the result
print(f"{celsius}°C is equal to {fahrenheit}°F")

# Python comparison operators example
a = 10
b = 5

# Equal to
print(f"{a} == {b}: {a == b}")  # False

# Not equal to
print(f"{a} != {b}: {a != b}")  # True

# Greater than
print(f"{a} > {b}: {a > b}")    # True

# Less than
print(f"{a} < {b}: {a < b}")    # False

# Greater than or equal to
print(f"{a} >= {b}: {a >= b}")  # True

# Less than or equal to
print(f"{a} <= {b}: {a <= b}")  # False

# Nested if example to check if a number is positive, negative, or zero
# And if positive, check if it's even or odd

num = int(input("Enter a number: "))

if num > 0:
    print("Positive number")
    # Nested if to check if the positive number is even or odd
    if num % 2 == 0:
        print("Even number")
    else:
        print("Odd number")
elif num < 0:
    print("Negative number")
else:
    print("Zero")

# Example of different selection structures
score = int(input("Enter your score: "))

# Simple if
if score >= 90:
    print("Excellent!")

# if-else
if score >= 60:
    print("You passed.")
else:
    print("You failed.")

# if-elif-else
if score >= 90:
    grade = "A"
elif score >= 80:
    grade = "B"
elif score >= 70:
    grade = "C"
elif score >= 60:
    grade = "D"
else:
    grade = "F"
print(f"Your grade is {grade}")

# Ternary operator
result = "Pass" if score >= 60 else "Fail"
print(result)

# Example of for loop in Python
# Printing each element in a list
fruits = ["apple", "banana", "cherry"]
for fruit in fruits:
    print(fruit)

# Using range function with for loop
print("Numbers from 1 to 5:")
for i in range(1, 6):
    print(i)

# Using for loop with string
name = "Python"
for char in name:
    print(char)

# Break statement example
print("Break example:")
for i in range(1, 11):
    if i == 6:
        print("Breaking the loop at i =", i)
        break
    print(i, end=" ")
print("\nLoop ended")

# Continue statement example
print("\nContinue example:")
for i in range(1, 11):
    if i % 2 == 0:
        continue
    print(i, end=" ")
print("\nOnly odd numbers were printed")

# Using for loop to print numbers from 1 to 10
print("Using for loop:")
for i in range(1, 11):
    print(i, end=" ")

print("\n\nUsing while loop:")
# Using while loop to print numbers from 1 to 10
counter = 1
while counter <= 10:
    print(counter, end=" ")
    counter += 1

# Print star pattern using for loop
rows = 5

for i in range(1, rows + 1):
    # Print i stars in each row
    print("*" * i)

# Print star pattern using nested loops
rows = 5

for i in range(1, rows + 1):
    for j in range(1, i + 1):
        print("*", end="")
    print()  # New line after each row

# Function to find factorial of a given number
def factorial(n):
    # Check if input is valid
    if not isinstance(n, int) or n < 0:
        return "Invalid input. Please enter a non-negative integer."
    
    # Base case: factorial of 0 or 1 is 1
    if n == 0 or n == 1:
        return 1
    
    # Calculate factorial using iteration
    result = 1
    for i in range(2, n + 1):
        result *= i
    
    return result

# Test the function
number = int(input("Enter a number to find its factorial: "))
print(f"Factorial of {number} is {factorial(number)}")

# Program to find odd and even numbers from 1 to N

# Get input from user
N = int(input("Enter the value of N: "))

print("Even numbers from 1 to", N, "are:")
for i in range(1, N + 1):
    if i % 2 == 0:
        print(i, end=" ")

print("\nOdd numbers from 1 to", N, "are:")
for i in range(1, N + 1):
    if i % 2 != 0:
        print(i, end=" ")

# Program to create and display nested list

# Create a nested list
nested_list = [
    [1, 2, 3],
    [4, 5, 6],
    [7, 8, 9]
]

# Display the nested list
print("Nested List:", nested_list)

# Display each element using nested loops
print("\nElements of the nested list:")
for i in range(len(nested_list)):
    for j in range(len(nested_list[i])):
        print(f"nested_list[{i}][{j}] = {nested_list[i][j]}")

# Alternative way to display using enumerate
print("\nUsing enumerate:")
for i, inner_list in enumerate(nested_list):
    for j, value in enumerate(inner_list):
        print(f"Position ({i}, {j}): {value}")

# Global variable
total = 0

def add_numbers(a, b):
    # Local variables
    sum_result = a + b
    print(f"Local variable sum_result: {sum_result}")
    
    # Accessing global variable
    print(f"Global variable total before modification: {total}")
    
    # To modify global variable within function
    global total
    total = sum_result
    print(f"Global variable total after modification: {total}")
    
    return sum_result

# Main program
x = 5  # Local to main program
y = 10  # Local to main program

result = add_numbers(x, y)
print(f"Result: {result}")
print(f"Updated global total: {total}")

# This would cause an error because sum_result is local to add_numbers
# print(sum_result)  # NameError: name 'sum_result' is not defined

# Example of using math module
import math

# Using mathematical functions from math module
radius = 5
area = math.pi * math.pow(radius, 2)
print(f"Area of circle with radius {radius} is {area:.2f}")

# Using different import techniques
from math import sqrt, sin
angle = math.pi / 4
print(f"Square root of 25 is {sqrt(25)}")
print(f"Sine of {angle} radians is {sin(angle):.4f}")

# Importing with alias
import random as rnd
random_number = rnd.randint(1, 100)
print(f"Random number between 1 and 100: {random_number}")

# Function to check if a number is an Armstrong number
def is_armstrong(num):
    # Convert number to string to count digits
    num_str = str(num)
    n = len(num_str)
    
    # Calculate sum of each digit raised to power of number of digits
    armstrong_sum = 0
    for digit in num_str:
        armstrong_sum += int(digit) ** n
    
    # Check if sum equals the original number
    return armstrong_sum == num

# Function to check if a number is a palindrome
def is_palindrome(num):
    # Convert number to string and check if it reads the same forwards and backwards
    num_str = str(num)
    return num_str == num_str[::-1]

# Main program
number = int(input("Enter a number: "))

# Check if the number is an Armstrong number
if is_armstrong(number):
    print(f"{number} is an Armstrong number")
else:
    print(f"{number} is not an Armstrong number")

# Check if the number is a palindrome
if is_palindrome(number):
    print(f"{number} is a palindrome")
else:
    print(f"{number} is not a palindrome")

# Example using math module
import math

# Basic constants
print(f"Value of pi: {math.pi}")
print(f"Value of e: {math.e}")

# Trigonometric functions (argument in radians)
angle = math.pi / 3  # 60 degrees
print(f"Sine of {angle:.2f} radians: {math.sin(angle):.4f}")
print(f"Cosine of {angle:.2f} radians: {math.cos(angle):.4f}")
print(f"Tangent of {angle:.2f} radians: {math.tan(angle):.4f}")

# Logarithmic and exponential functions
x = 10
print(f"Natural logarithm of {x}: {math.log(x):.4f}")
print(f"Logarithm base 10 of {x}: {math.log10(x):.4f}")
print(f"e raised to power {x}: {math.exp(x):.4f}")

# Other functions
print(f"Square root of 25: {math.sqrt(25)}")
print(f"Ceiling of 4.3: {math.ceil(4.3)}")
print(f"Floor of 4.7: {math.floor(4.7)}")

# Variable scope demonstration

# Global variable
count = 0

def outer_function():
    # Enclosing scope variable
    name = "Python"
    
    def inner_function():
        # Local variable
        age = 30
        # Accessing global variable
        global count
        count += 1
        # Accessing enclosing variable
        print(f"Inside inner_function: name is {name}")
        print(f"Inside inner_function: age is {age}")
        print(f"Inside inner_function: count is {count}")
    
    # Local variable to outer_function
    language = "Programming"
    print(f"Inside outer_function: name is {name}")
    print(f"Inside outer_function: language is {language}")
    print(f"Inside outer_function: count is {count}")
    
    # Call inner function
    inner_function()
    
    # This would cause an error - age is local to inner_function
    # print(age)

# Main program
print(f"Global scope: count is {count}")
outer_function()
print(f"Global scope after function call: count is {count}")

# These would cause errors - they are local to functions
# print(name)
# print(language)

# Program to swap two elements in a list

# Create a list
my_list = [10, 20, 30, 40, 50]
print("Original list:", my_list)

# Get positions to swap
pos1 = int(input("Enter first position (index starts from 0): "))
pos2 = int(input("Enter second position (index starts from 0): "))

# Swap elements using a temporary variable
if 0 <= pos1 < len(my_list) and 0 <= pos2 < len(my_list):
    # Swapping
    temp = my_list[pos1]
    my_list[pos1] = my_list[pos2]
    my_list[pos2] = temp
    
    print(f"List after swapping elements at positions {pos1} and {pos2}:", my_list)
else:
    print("Invalid positions! Positions should be within list range.")

# Swap using Python's tuple unpacking (more pythonic)
if 0 <= pos1 < len(my_list) and 0 <= pos2 < len(my_list):
    my_list[pos1], my_list[pos2] = my_list[pos2], my_list[pos1]
    print(f"List after swapping elements at positions {pos1} and {pos2}:", my_list)

# Creating a nested list (3x3 matrix)
matrix = [
    [1, 2, 3],
    [4, 5, 6],
    [7, 8, 9]
]

# Accessing elements
print("Complete matrix:", matrix)
print("First row:", matrix[0])
print("Element at row 1, column 2:", matrix[0][1])  # Output: 2

# Modifying elements
matrix[1][1] = 50
print("Matrix after modification:", matrix)

# Iterating through a nested list
print("\nPrinting the matrix:")
for row in matrix:
    for element in row:
        print(element, end=" ")
    print()  # New line after each row

# String operations demonstration
text = "Python Programming"

# Indexing
print("First character:", text[0])
print("Last character:", text[-1])

# Slicing
print("First word:", text[:6])
print("Second word:", text[7:])
print("Middle characters:", text[3:10])
print("Reverse:", text[::-1])

# String methods
print("Uppercase:", text.upper())
print("Lowercase:", text.lower())
print("Replace 'P' with 'J':", text.replace("P", "J"))
print("Split by space:", text.split())
print("Count 'm':", text.count('m'))
print("Find 'gram':", text.find("gram"))

# Check operations
print("Is alphanumeric?", text.isalnum())
print("Starts with 'Py'?", text.startswith("Py"))
print("Ends with 'ing'?", text.endswith("ing"))

# Program to find sum of all elements in a list

# Method 1: Using built-in sum() function
def sum_list_builtin(numbers):
    return sum(numbers)

# Method 2: Using a loop
def sum_list_loop(numbers):
    total = 0
    for num in numbers:
        total += num
    return total

# Create a sample list
my_list = [10, 20, 30, 40, 50]
print("List:", my_list)

# Calculate sum using built-in function
print("Sum using built-in function:", sum_list_builtin(my_list))

# Calculate sum using loop
print("Sum using loop:", sum_list_loop(my_list))

# Indexing and slicing demonstration
fruits = ["apple", "banana", "cherry", "date", "elderberry", "fig"]
print("Original list:", fruits)

# Indexing
print("\nIndexing examples:")
print("First item:", fruits[0])  # apple
print("Last item:", fruits[-1])  # fig
print("Third item:", fruits[2])  # cherry

# Slicing
print("\nSlicing examples:")
print("First three items:", fruits[:3])  # ['apple', 'banana', 'cherry']
print("Last three items:", fruits[-3:])  # ['date', 'elderberry', 'fig']
print("Middle items:", fruits[2:4])  # ['cherry', 'date']
print("Every second item:", fruits[::2])  # ['apple', 'cherry', 'elderberry']
print("Reversed list:", fruits[::-1])  # ['fig', 'elderberry', 'date', 'cherry', 'banana', 'apple']

# Creating tuples
empty_tuple = ()
single_item_tuple = (1,)  # Comma is necessary for single item
mixed_tuple = (1, "Hello", 3.14, True)
nested_tuple = (1, 2, (3, 4), 5)

# Accessing tuple elements
print("First item:", mixed_tuple[0])  # 1
print("Last item:", mixed_tuple[-1])  # True
print("Nested tuple element:", nested_tuple[2][0])  # 3

# Slicing tuple
print("First two items:", mixed_tuple[:2])  # (1, "Hello")

# Tuple unpacking
a, b, c, d = mixed_tuple
print("Unpacked values:", a, b, c, d)

# Tuple methods
print("Count of 1:", mixed_tuple.count(1))  # 1
print("Index of 'Hello':", mixed_tuple.index("Hello"))  # 1

# Tuple operations
combined_tuple = mixed_tuple + nested_tuple
repeated_tuple = mixed_tuple * 2
print("Combined tuple:", combined_tuple)
print("Repeated tuple:", repeated_tuple)

# This will cause error as tuples are immutable
# mixed_tuple[0] = 100  # TypeError: 'tuple' object does not support item assignment