1. Python Data Structures

1. Lists and Tuples:

o Write a Python program to find the second largest number in a  list

def find_second_largest(numbers):

    if len(numbers) < 2:

        raise ValueError("List must contain at least two elements")

    # Initialize the largest and second largest numbers

    largest = second_largest = float('-inf')

    for number in numbers:

        if number > largest:

            # Update second largest before updating largest

            second_largest = largest

            largest = number

        elif largest > number > second_largest:

            second_largest = number

    if second_largest == float('-inf'):

        raise ValueError("There is no second largest number")

        return second_largest

# Example usage:

numbers = [10, 5, 20, 20, 30, 40, 40]

try:

    result = find_second_largest(numbers)

    print(f"The second largest number is: {result}")

except ValueError as e:

    print(e)

Another Method

lst = [2,3,45,6,2,23,66,3,2,65,7,2,2,657]

lst2 = [0]

for i in lst:

    if lst2[-1]<i:

        lst2.append(i)

lst2[-2] 

o Write a Python program to merge two tuples into a dictionary.

def merge_tuples_to_dict(keys, values):

    if len(keys) != len(values):

        raise ValueError("The number of keys must be equal to the number of values")

    # Zip the keys and values together and create a dictionary

    merged_dict = dict(zip(keys, values))

    return merged_dict

# Example usage:

keys_tuple = ('a', 'b', 'c')

values_tuple = (1, 2, 3)

try:

    result = merge_tuples_to_dict(keys_tuple, values_tuple)

    print(f"Merged dictionary: {result}")

except ValueError as e:

    print(e)

2. Dictionaries and Sets:

o Write a Python program to count the frequency of each word in a given string using a dictionary.

def count_word_frequencies(text):

    # Convert the string to lowercase to make the count case-insensitive

    text = text.lower()

    # Split the text into words

    words = text.split()

    # Initialize an empty dictionary to store word frequencies

    word_count = {}

    # Count the frequency of each word

    for word in words:

        if word in word_count:

            word_count[word] += 1

        else:

            word_count[word] = 1

    return word_count

# Example usage:

input_text = "Hello world! Welcome to the world of Python. Python is amazing."

# Remove punctuation for cleaner word counting

import string

translator = str.maketrans('', '', string.punctuation)

cleaned_text = input_text.translate(translator)

result = count_word_frequencies(cleaned_text)

print(f"Word frequencies: {result}")

Another Method:

s = "Hellow this is a string and i'll use thsi for this snippet of code"

hash = {}

for i in s.lower():

    if i not in  hash:

        hash[i] = 1

    else:

        hash[i]+=1 

o Write a Python program to find the union and intersection of two sets.

def set_operations(set1, set2):

    # Calculate the union of two sets

    union_set = set1 | set2  # or set1.union(set2)

    # Calculate the intersection of two sets

    intersection_set = set1 & set2  # or set1.intersection(set2)

    return union_set, intersection_set

# Example usage:

set1 = {1, 2, 3, 4, 5}

set2 = {4, 5, 6, 7, 8}

union_result, intersection_result = set_operations(set1, set2)

print(f"Union of the sets: {union_result}")

print(f"Intersection of the sets: {intersection_result}")