Count characters in a text file - Python Programming Exercise

import sys

def count_character_in_file(file_name, character):
    """
    Counts how many times a specific character appears in a given file.
    
    Parameters:
    file_name (str): The name of the file to search.
    character (str): The character to search for in the file.
    
    Returns:
    int: The count of occurrences of the specified character.
    """
    count = 0
    try:
        # Open the file in read mode
        with open(file_name, 'r') as file:
            # Read the content of the file
            content = file.read()
            
            # Count the occurrences of the specified character
            count = content.count(character)
        
        return count
        
    except FileNotFoundError:
        print(f"The file '{file_name}' was not found.")
        return -1  # Indicates file was not found
    except Exception as e:
        print(f"An error occurred: {e}")
        return -1  # Indicates an unexpected error

# Main program execution
if __name__ == "__main__":
    # Check if the correct number of arguments are provided
    if len(sys.argv) == 3:
        # Extract command-line arguments
        file_name = sys.argv[1]
        character = sys.argv[2]
        
        # Validate that only one character is provided
        if len(character) != 1:
            print("Please provide exactly one character to search for.")
        else:
            # Call the function to count the character in the file
            count = count_character_in_file(file_name, character)
            if count != -1:
                print(f"The character '{character}' appears {count} times in the file '{file_name}'.")
    else:
        # Ask the user for the file name and character if no command-line args
        file_name = input("Please enter the file name: ")
        character = input("Please enter the character to search for: ")
        
        # Validate that only one character is provided
        if len(character) != 1:
            print("Please provide exactly one character to search for.")
        else:
            # Call the function to count the character in the file
            count = count_character_in_file(file_name, character)
            if count != -1:
                print(f"The character '{character}' appears {count} times in the file '{file_name}'.")

 Output

Assume example.txt contains:
apple
banana
avocado

If you run the following command:
python count_character.py example.txt a

The program will output:
The character 'a' appears 6 times in the file 'example.txt'.

If the file does not exist or an error occurs, the program will display:
The file 'nonexistent.txt' was not found.