Simple Calculator with Symbol and Letter-Based Operators in Python

Program Overview

This Python program reads two numbers and a character from the user.
Based on the character input, it performs one of the following operations:

• +, A, a → Addition
• -, S, s → Subtraction
• *, M, m → Multiplication
• /, D, d → Integer division of the first number by the second

If the character is not recognized, the program displays "Invalid operator".

Python Code:

# Read inputs
num1 = float(input("Enter the first number: "))
op = input("Enter an operator (+, -, *, /, A/S/M/D or a/s/m/d): ").strip().lower()
num2 = float(input("Enter the second number: "))

# Perform operation
if op in ['+', 'a']:
    result = num1 + num2
elif op in ['-', 's']:
    result = num1 - num2
elif op in ['*', 'm']:
    result = num1 * num2
elif op in ['/', 'd']:
    if num2 != 0:
        result = int(num1) // int(num2)
    else:
        result = "Error: Division by zero is not allowed."
else:
    result = "Invalid operator"

# Display result
print("Result:", result)

Sample Output:

Enter the first number: 10  
Enter an operator: m  
Enter the second number: 3  
Result: 30.0

Enter the first number: 15  
Enter an operator: /  
Enter the second number: 4  
Result: 3

Step-by-Step Explanation:

- The operator is normalized using .lower() to handle both uppercase and lowercase letters
- The program checks the operator against known symbols and letters
- Integer division is performed using // after converting inputs to int
- Division by zero is handled with a conditional check
- If the operator is invalid, a message is displayed