Python program to check if a number is even or odd. -

Understanding Even and Odd Numbers

In mathematics, numbers can be classified into two main categories: even and odd. An even number is an integer that is exactly divisible by 2 (e.g., -4, -2, 0, 2, 4). Conversely, an odd number is an integer that, when divided by 2, has a remainder of 1 (e.g., -3, -1, 1, 3).

The ability to determine whether a number is even or odd is a fundamental concept in programming, often serving as an introductory exercise for beginners. In this article, we will explore how to write a simple Python program to perform this check.

Setting Up Your Python Environment

Before we dive into the code, make sure you have Python installed on your system. You can download it from the official Python website. If you prefer online coding, platforms like Replit or Jupyter Notebook can also be used to execute Python code.

The Basic Logic

To determine if a number is even or odd, you can use the modulus operator %, which gives the remainder of a division operation. The logic is straightforward:

If number % 2 == 0, the number is even.
If number % 2 != 0, the number is odd.

Writing the Program

Let’s write a simple Python program to implement this logic. The program will prompt the user to input a number, check if it’s even or odd, and then display the result.

# Function to check if a number is even or odd
def check_even_odd(number):
    if number % 2 == 0:
        return "even"
    else:
        return "odd"

# Main function to run the program
def main():
    try:
        # Prompting the user for input
        user_input = int(input("Enter an integer: "))

        # Checking if the number is even or odd
        result = check_even_odd(user_input)

        # Displaying the result
        print(f"The number {user_input} is {result}.")

    except ValueError:
        print("Please enter a valid integer.")

# Entry point of the program
if __name__ == "__main__":
    main()

Explanation of the Code

Function Definition:

We define a function check_even_odd(number) that takes an integer as input.
Inside the function, we use an if-else statement to check if the number is even or odd and return the corresponding string.

Main Function:

The main() function is where the program execution begins.
We use input() to get user input, and int() to convert the input string to an integer.
The program handles any non-integer inputs using a try-except block to catch ValueError.

Result Output:

Finally, we print the result to inform the user whether the input number is even or odd.

Testing the Program

You can run this program multiple times with different inputs. Here are a few examples:

Input: 10
Output: The number 10 is even.
Input: 7
Output: The number 7 is odd.
Input: -4
Output: The number -4 is even.
Input: 0
Output: The number 0 is even.

Expanding the Program

While the basic program serves its purpose well, you might want to consider expanding its functionality. Here are a few ideas:

Check Multiple Numbers: Allow users to input a list of numbers and check each one.
User-Friendly Interface: Create a graphical user interface (GUI) using libraries like Tkinter.
Web Application: Use Flask or Django to build a web app that checks if numbers are even or odd.

Conclusion

In this article, we explored how to write a simple Python program to check if a number is even or odd. This foundational exercise not only reinforces basic programming concepts like functions and conditionals but also lays the groundwork for more advanced topics.

With Python’s simplicity and readability, tasks such as checking if a number is even or odd become straightforward and enjoyable. As you continue to learn and grow your coding skills, remember that even the simplest programs can lead to deeper understanding and creativity in programming.

So, fire up your Python environment and start experimenting with the code provided. Happy coding!