<div class="row py-2">
                <div class="col-12 mx-auto">
                    <div class="row">
                    <div class="col-12 mx-auto">
                        <button type="button" class="btn btn-primary w-auto me-1 ">Primary</button>
                        <button type="button" class="btn btn-secondary w-auto me-1 ">Secondary</button>
                        <button type="button" class="btn btn-info w-auto me-1 ">Info</button>
                        <button type="button" class="btn btn-success w-auto me-1 ">Success</button>
                        <button type="button" class="btn btn-warning w-auto me-1 ">Warning</button>
                        <button type="button" class="btn btn-danger w-auto me-1 ">Danger</button>
                        <button type="button" class="btn btn-light w-auto me-1 ">Light</button>
                        <button type="button" class="btn btn-dark w-auto me-1 ">Dark</button>
                    </div>
                    </div>
                </div>
                </div>/* Your button styles */
                .btn {
                    transition: 0.5s !important;
                    background-size: 200% auto;
                    color: white;
                    box-shadow: 0 0 20px #eee;
                    border-radius: 10px !important;
                    border-style: none !important;
                    margin-left: 10px;
                    margin-bottom: 5px;
                }
                .btn:hover {
                    background-position: right center;
                    color: #fff;
                    text-decoration: none;
                }
                .btn-primary {
                    background-image: linear-gradient(to right, #02AAB0 0%, #00CDAC 51%, #02AAB0 100%);
                }
                .btn-secondary {
                    background-image: linear-gradient(to right, #ff6e7f 0%, #bfe9ff 51%, #ff6e7f 100%);
                }
                .btn-dark{
                    background-image: linear-gradient(to right, #232526 0%, #414345 51%, #232526 100%);
                }
                .btn-light, .btn-light:hover{
                    background-image: linear-gradient(to right, #ECE9E6 0%, #FFFFFF 51%, #ECE9E6 100%);
                    color: black;
                }
                .btn-info {
                    background-image: linear-gradient(to right, #005C97 0%, #363795  51%, #005C97  100%);
                }
                .btn-success {
                    background-image: linear-gradient(to right, #56ab2f 0%, #a8e063  51%, #56ab2f  100%);
                }
                .btn-warning{
                    background-image: linear-gradient(to right, #F2994A 0%, #F2C94C  51%, #F2994A  100%);
                }
                .btn-danger{
                    background-image: linear-gradient(to right, #cb2d3e 0%, #ef473a  51%, #cb2d3e  100%);
                }

Show Code

 # This function adds two numbers
def add(x, y):
    return x + y

# This function subtracts two numbers
def subtract(x, y):
    return x - y

# This function multiplies two numbers
def multiply(x, y):
    return x * y

# This function divides two numbers
def divide(x, y):
    return x / y


print("Select operation.")
print("1.Add")
print("2.Subtract")
print("3.Multiply")
print("4.Divide")

while True:
    # take input from the user
    choice = input("Enter choice(1/2/3/4): ")

    # check if choice is one of the four options
    if choice in ('1', '2', '3', '4'):
        try:
            num1 = float(input("Enter first number: "))
            num2 = float(input("Enter second number: "))
        except ValueError:
            print("Invalid input. Please enter a number.")
            continue

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

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

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

        elif choice == '4':
            print(num1, "/", num2, "=", divide(num1, num2))
        
        # check if user wants another calculation
        # break the while loop if answer is no
        next_calculation = input("Let's do next calculation? (yes/no): ")
        if next_calculation == "no":
          break
    else:
        print("Invalid Input")

 <div class="progress mb-3">
                    <div class="progress-bar bg-primary" role="progressbar" style="width: 50%" aria-valuenow="50" aria-valuemin="0" aria-valuemax="100"></div>
                    </div>
                    <div class="progress mb-3">
                    <div class="progress-bar bg-secondary" role="progressbar" style="width: 75%" aria-valuenow="75" aria-valuemin="0" aria-valuemax="100"></div>
                    </div>
                    <div class="progress mb-3">
                    <div class="progress-bar bg-success" role="progressbar" style="width: 80%" aria-valuenow="80" aria-valuemin="0" aria-valuemax="100"></div>
                    </div>
                    <div class="progress mb-3">
                    <div class="progress-bar bg-info" role="progressbar" style="width: 10%" aria-valuenow="10" aria-valuemin="0" aria-valuemax="100"></div>
                    </div>
                    <div class="progress mb-3">
                    <div class="progress-bar bg-warning" role="progressbar" style="width: 30%" aria-valuenow="30" aria-valuemin="0" aria-valuemax="100"></div>
                    </div>
                    <div class="progress mb-3">
                    <div class="progress-bar bg-danger" role="progressbar" style="width: 50%" aria-valuenow="50" aria-valuemin="0" aria-valuemax="100"></div>
                    </div>
                    <div class="progress mb-3">
                    <div class="progress-bar bg-dark" role="progressbar" style="width: 100%" aria-valuenow="100" aria-valuemin="0" aria-valuemax="100"></div>
                    </div>