Simple Calculator Implementation in Python

The following code demonstrates a basic calculator that can perform addition, subtraction, multiplication, and division between two numbers.

Example 1: Basic Calculator

# Define functions
def add(x, y):
    """Addition"""
    return x + y

def subtract(x, y):
    """Subtraction"""
    return x - y

def multiply(x, y):
    """Multiplication"""
    return x * y

def divide(x, y):
    """Division"""
    return x / y

# User input
print("Select operation:")
print("1. Addition")
print("2. Subtraction")
print("3. Multiplication")
print("4. Division")

choice = input("Enter your choice (1/2/3/4):")

num1 = int(input("Enter the first number: "))
num2 = int(input("Enter the second number: "))

if choice == '1':
    print(f"{num1} + {num2} = {add(num1, num2)}")

elif choice == '2':
    print(f"{num1} - {num2} = {subtract(num1, num2)}")

elif choice == '3':
    print(f"{num1} * {num2} = {multiply(num1, num2)}")

elif choice == '4':
    print(f"{num1} / {num2} = {divide(num1, num2)}")

else:
    print("Invalid input")

Example Output:

Select operation:
1. Addition
2. Subtraction
3. Multiplication
4. Division
Enter your choice (1/2/3/4): 2
Enter the first number: 5
Enter the second number: 2
5 - 2 = 3

Example 2: Calculator with a Loop

The following code expands the calculator to run continuously until the user chooses to exit.

# Simple Calculator Program

# Define function for addition
def add(x, y):
    return x + y

# Define function for subtraction
def subtract(x, y):
    return x - y

# Define function for multiplication
def multiply(x, y):
    return x * y

# Define function for division
def divide(x, y):
    if y != 0:
        return x / y
    else:
        return "Cannot divide by zero"

# Main program loop
while True:
    print("\nSelect an operation:")
    print("1. Addition")
    print("2. Subtraction")
    print("3. Multiplication")
    print("4. Division")
    print("5. Exit")

    choice = input("Enter the choice number: ")

    if choice in ('1', '2', '3', '4'):
        num1 = float(input("Enter the first number: "))
        num2 = float(input("Enter the second number: "))

        if choice == '1':
            print(f"Result: {add(num1, num2)}")
        elif choice == '2':
            print(f"Result: {subtract(num1, num2)}")
        elif choice == '3':
            print(f"Result: {multiply(num1, num2)}")
        elif choice == '4':
            print(f"Result: {divide(num1, num2)}")
    elif choice == '5':
        print("Exiting the program.")
        break
    else:
        print("Invalid option, please try again.")

Example Output:

Select an operation:
1. Addition
2. Subtraction
3. Multiplication
4. Division
5. Exit
Enter the choice number: 4
Enter the first number: 10
Enter the second number: 2
Result: 5.0

This implementation offers a continuous loop that enables the user to perform multiple calculations until they choose to exit the program.