Switch case or match case?

[menator01]

Are you trying to use the new structural pattern matching introduced in Python 3.10? As far as I know that is the only Python feature that uses "case" as a keyword. I have not installed 3.10 yet, but I believe the code would look like this:

while True:
    op = input(Select operation +, -, *, /: ")
    if op not in "+-*/":
        print("Invalid Input")
    else:
        num1 = float(input("Enter first number: "))
        num2 = float(input("Enter second number: "))
        match choice:
            case ['+']:
                print(num1, "+", num2, "=", num1 + num2)
            case ['-']:
                print(num1, "-", num2, "=", num1 - num2)
            case ['*']:
                print(num1, "*", num2, "=", num1 * num2)
            case ['/']:
                print(num1, "/", num2, "=", num1 / num2)
 
    if input("Let's do next calculation? (yes/no): ") == "no":
        break

I look forward to using this new feature. If I had to solve this problem without structured pattern matching I would probably fall back on using a dictionary.

operations = {
    "+": lambda a, b: print(f"{a} + {b} = {a+b}"),
    "-": lambda a, b: print(f"{a} - {b} = {a-b}"),
    "*": lambda a, b: print(f"{a} * {b} = {a*b}"),
    "/": lambda a, b: print(f"{a} / {b} = {a/b}"),
}

while True:
    op = input(f"Select operation {', '.join(operations.keys())}: ")
    if op not in operations:
        print("Invalid Input")
    else:
        num1 = float(input("Enter first number: "))
        num2 = float(input("Enter second number: "))
        operations[op](num1, num2)

    if input("Let's do next calculation? (yes/no): ") == "no":
        break

I had to tweak the code a little to get it to work.

while True:
    op = input("Select operation +, -, *, /: ")
    if op not in "+-*/":
        print("Invalid Input")
    else:
        num1 = float(input("Enter first number: "))
        num2 = float(input("Enter second number: "))
        match op:
            case '+':
                print(num1, "+", num2, "=", num1 + num2)
            case '-':
                print(num1, "-", num2, "=", num1 - num2)
            case '*':
                print(num1, "*", num2, "=", num1 * num2)
            case '/':
                print(num1, "/", num2, "=", num1 / num2)

    if input("Let's do next calculation? (yes/no): ") == "no":
        break

Output:
Select operation +, -, *, /: +
Enter first number: 1
Enter second number: 1
1.0 + 1.0 = 2.0
Let's do next calculation? (yes/no): no