Build a terminal-based calculator

Creating a terminal-based calculator is a great way to practice programming fundamentals like input handling, basic operations, and control flow. Below is a Python example for a simple terminal calculator that supports addition, subtraction, multiplication, and division with continuous use until the user decides to exit.

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

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

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

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

def calculator():
    print("Simple Terminal Calculator")
    print("Operations: +, -, *, /")
    print("Type 'exit' to quit.n")

    while True:
        num1 = input("Enter first number: ")
        if num1.lower() == 'exit':
            print("Exiting calculator. Goodbye!")
            break

        num2 = input("Enter second number: ")
        if num2.lower() == 'exit':
            print("Exiting calculator. Goodbye!")
            break

        operation = input("Choose operation (+, -, *, /): ")
        if operation.lower() == 'exit':
            print("Exiting calculator. Goodbye!")
            break

        try:
            num1 = float(num1)
            num2 = float(num2)
        except ValueError:
            print("Invalid number input. Please enter valid numbers.n")
            continue

        if operation == '+':
            print(f"Result: {add(num1, num2)}n")
        elif operation == '-':
            print(f"Result: {subtract(num1, num2)}n")
        elif operation == '*':
            print(f"Result: {multiply(num1, num2)}n")
        elif operation == '/':
            result = divide(num1, num2)
            print(f"Result: {result}n")
        else:
            print("Invalid operation. Please choose +, -, *, or /.n")

if __name__ == "__main__":
    calculator()

How it works:

• The user inputs two numbers and an operation.

• The program performs the operation.

• If invalid input or operation is entered, it prompts the user again.

• Type exit anytime to quit.

Would you like me to extend this with more functions or a more advanced interface?