Day 100: Python Program to Count the Frequency of Each Word in a String using Dictionary

def count_word_frequency(input_string):

    """

    Counts the frequency of each word in the input string.

    Args:

        input_string (str): The input string.

    Returns:

        dict: A dictionary with words as keys and their frequencies as values.

    """

    words = input_string.split()

    word_count = {}

    for word in words:

        word = word.lower()  

        if word in word_count:

            word_count[word] += 1

        else:

            word_count[word] = 1

       return word_count

input_string = input("Enter a string: ")

word_frequency = count_word_frequency(input_string)

print("\nWord Frequency:")

for word, count in word_frequency.items():

    print(f"'{word}': {count}")

#source code --> clcoding.com 

 Code explanation:

Function Definition

def count_word_frequency(input_string):

Purpose: This defines a function named count_word_frequency that accepts one parameter, input_string. The function calculates how many times each word appears in the given string.

Docstring

    """

    Counts the frequency of each word in the input string.

    Args:

        input_string (str): The input string.

    Returns:

        dict: A dictionary with words as keys and their frequencies as values.

    """

Purpose: Provides documentation for the function. It explains:

What the function does: It counts the frequency of words in the string.

Arguments: input_string, the string input.

Return Value: A dictionary where each word is a key, and its value is the word’s frequency.

Splitting the String

    words = input_string.split()

What it does:

The split() method divides the string into words, using spaces as the default separator.

Example: "Hello world!" becomes ['Hello', 'world!'].

Initialize the Dictionary

    word_count = {}

What it does: Creates an empty dictionary word_count to store each word as a key and its frequency as the corresponding value.

Loop Through Words

    for word in words:

What it does: Iterates through the list of words obtained from the split() method.

Normalize the Word

        word = word.lower()

What it does: Converts the current word to lowercase to handle case insensitivity.

Example: "Word" and "word" are treated as the same.

Update Word Count in Dictionary

Check if Word Exists

        if word in word_count:

            word_count[word] += 1

What it does:

Checks if the word is already present in the dictionary word_count.

If it is, increments its frequency by 1.

Add Word to Dictionary

        else:

            word_count[word] = 1

What it does:

If the word is not already in the dictionary, adds it as a new key and sets its frequency to 1.

Return the Dictionary

    return word_count

What it does: Returns the word_count dictionary containing the word frequencies.

User Input

input_string = input("Enter a string: ")

What it does: Prompts the user to input a string and stores it in the variable input_string.

Call the Function

word_frequency = count_word_frequency(input_string)

What it does: Calls the count_word_frequency function, passing the user's input string, and stores the resulting dictionary in the word_frequency variable.

Display the Results

print("\nWord Frequency:")

What it does: Prints a header Word Frequency: to label the output.

Loop Through Dictionary

for word, count in word_frequency.items():

    print(f"'{word}': {count}")

What it does:

Iterates through the word_frequency dictionary using the items() method, which returns key-value pairs (word and frequency).

Prints each word and its frequency in the format '{word}': {count}.