🔢 Building a Simple Python Calculator Using Input and Output

One of the best ways to practice Python—especially as a beginner—is by building simple projects that simulate real-life applications. One such project commonly worked on is a basic command-line calculator. It covers essential Python skills like functions, conditionals, loops, input handling, and exception management. In this blog post, I’ll walk you through how the project works and what makes it a great learning tool.

🧮 Project Overview

The calculator allows users to perform five basic arithmetic operations:

1. Addition
2. Subtraction
3. Multiplication
4. Division
5. Exponentiation

It prompts users to choose an operation and then handles input accordingly. Here’s the GitHub link to the project if you want to check out the full code.

🛠️ How It Works

The main function action(op) handles the user’s choice and routes it to the corresponding function.

👇 Input Example

print("Welcome to the calculator!")
print("What would you like to do?")
print("1. Addition")
print("2. Subtraction")
print("3. Multiplication")
print("4. Division")
print("5. Exponentiation")

op = input("Enter your choice: ")
print(action(op))

Depending on the input (op), the action function:

• Parses user input (with split(',') for multiple values)
• Converts string input into integers
• Calls the right math function with *args or positional arguments

🔍 Key Functions

➕ Addition

def add(*values):
    total = 0
    for value in values:
        total += value
    return total

Takes any number of arguments and returns their sum.

➖ Subtraction

def sub(main_value, *values):
    total = main_value
    for value in values:
        total += value  # Negative values passed in
    return total

Subtracts all values from an initial value. (Negative values are passed to simulate subtraction.)

✖️ Multiplication

def mult(*values):
    total = 1
    for value in values:
        total *= value
    return total

Multiplies all input values.

➗ Division

def div(num, den):
    return num / den

Handles basic division. Catches division by zero errors using try/except.

🔼 Exponentiation

def expon(base, exp):
    return base ** exp

Raises a number to a given power.

💡 Why This Project Matters

• User Input Handling: You get hands-on experience with input(), string manipulation, and validation.
• Function Usage: A great way to practice breaking logic into reusable components.
• Error Handling: Each function has a try/except block to catch invalid inputs or runtime errors.
• Real-Life Simulation: It’s a mini tool that mirrors how real-world calculators work under the hood.

🚀 Future Improvements

Here are a few ideas to expand this project:

• Add support for float numbers
• Include more operations (like square root, modulus)
• Improve user experience with a loop and option to exit
• Build a GUI version with Tkinter or PyQt

🔗 Check Out the Code

Want to try it out or make improvements? Check out the code on GitHub:

👉 View Project on GitHub

Feel free to clone it, experiment, and level up your Python skills!