Python Calculator

rezanezhadfatemeh0-cmd — Sun, 05 Oct 2025 21:50:54 +0000

Simple Python Calculator

A clean command-line calculator built with Python. Performs basic arithmetic operations with error handling.

This calculator lets you:

Each math operation gets its own function:

def add(x, y):
    return x + y

def divide(x, y):
    if y == 0:
        return "Error! Division by zero."
    return x / y

Why separate functions? Makes the code easy to test and reuse.

The calculator runs in a loop, showing a menu each time:

1. Add
2. Subtract
3. Multiply
4. Divide
5. Exit

Users pick a number, enter two values, and get their answer. Press 5 to exit.

Two types of errors are handled:

try:
    num1 = float(input("Enter first number: "))
except ValueError:
    print("Invalid input! Please enter numbers only.")

✓ Simple menu interface

✓ Works with decimals (3.14, 2.5)

✓ Works with negatives (-5, -10)

✓ Doesn't crash on bad input

✓ Only 50 lines of code

Enter choice (1/2/3/4/5): 1
Enter first number: 10
Enter second number: 5
10.0 + 5.0 = 15.0

Building this taught me:

Ideas for future versions:

python calculator.py

Tech: Python 3

Lines of Code: ~50

View the complete code on GitHub: Simple-Calculator

Simple, functional, and ready to use.