app.py

import gradio as gr


def add(a, b):
    """Add two numbers."""
    return a + b


def subtract(a, b):
    """Subtract second number from first."""
    return a - b


def multiply(a, b):
    """Multiply two numbers."""
    return a * b


def divide(a, b):
    """Divide first number by second."""
    if b == 0:
        raise gr.Error("Error: Division by zero")
    return a / b


def square(a, b=None):
    """Square a number. Second parameter ignored."""
    return a * a


def calculate(operation, num1, num2):
    """Main calculation function that routes to appropriate operation."""
    if operation == "Add":
        return add(num1, num2)
    elif operation == "Subtract":
        return subtract(num1, num2)
    elif operation == "Multiply":
        return multiply(num1, num2)
    elif operation == "Divide":
        return divide(num1, num2)
    elif operation == "Square":
        return square(num1)
    else:
        return "Error: Unknown operation"


with gr.Blocks(title="Calculator App") as demo:
    gr.Markdown("# Simple Calculator")
    gr.Markdown("Choose an operation and enter numbers to calculate.")

    num1 = gr.Number(label="First Number", value=0)
    operation = gr.Dropdown(
        choices=["Add", "Subtract", "Multiply", "Divide", "Square"],
        label="Operation",
        value="Add",
    )
    num2 = gr.Number(label="Second Number (ignored for Square)", value=0)

    calculate_btn = gr.Button("Calculate", variant="primary")

    result = gr.Textbox(label="Result", interactive=False)

    def update_visibility(operation):
        if operation == "Square":
            return gr.Number(visible=False)
        else:
            return gr.Number(visible=True)

    operation.change(fn=update_visibility, inputs=operation, outputs=num2)

    calculate_btn.click(fn=calculate, inputs=[operation, num1, num2], outputs=result)

    gr.Markdown("### Examples")
    gr.Examples(
        examples=[
            ["Add", 5, 3],
            ["Subtract", 10, 4],
            ["Multiply", 6, 7],
            ["Divide", 15, 3],
            ["Square", 4, 0],
        ],
        inputs=[operation, num1, num2],
    )

if __name__ == "__main__":
    demo.launch()